S.O.S.! It’s a Schwa!  

S.O.S.! It’s a Schwa!
By: Jura Kool

Schwa [ʃwa], the most commonly spoken phoneme (sound) in English, is pronounced [ə]. Schwa is not represented by a grapheme (letter).  Initially, we may start to panic when we realize a sound that is not represented by a letter or letters.  Struggling readers and spellers may want to shout “S.O.S.!” the distress signal used when we are in desperate need of help, realizing they have no idea how to spell this elusive sound. If we explore the schwa sound and know how it shows up in the English language, we can better understand when and how it is used and make better sense of the orthography (spelling) of English. If we can apply some simple encoding strategies, S.O.S. does not have to be a distress signal but can represent simultaneous oral spelling. 


If you ever struggled with spelling and you have never heard of the vowel sound Schwa, you may be suddenly getting flashbacks of sitting at your desk in the 2nd grade. The teacher suddenly dictates a multi-syllable word and your palms get sweaty, your awkward pencil grip tightens, knuckles whiten, and your heart races. Suddenly the survival part of your brain hijacks the frontal cortex part of your brain, preventing you from thinking clearly or retrieving information. The last two years of your academic career thus far have been no different. After all, your exposure to reading, writing, and spelling language started in kindergarten, and spelling then was just as tricky as it is now. You want to spell the word correctly; your mind races as you are stuck on just one vowel sound that keeps you from the accurate spelling of the word. Vowel sounds have always eluded you, and now we must worry about a Schwa? Whether you are a student, teacher, or parent and have never heard of a schwa, do not panic; most people have not. Turn that S.O.S. signal off in your brain and relax. It’s only a schwa! The most common vowel sound in English (Phonetics 2 - Vowels: Crash Course Linguistics #9 2020). You may think, “How can this be?”, “I have never heard of a Schwa? I thought there was a letter or group of letters for every vowel sound in English?”

S.O.S.! It’s a Schwa!

Schwa is the most frequently spoken phoneme (sound) in the English language. Schwa is not represented by a grapheme (letter). Once we explore the schwa sound and understand Schwa’s origin and how it occurs in words, we will better understand how it is represented in English orthography (spelling). To begin to do this, we need to debunk a couple of English spelling myths.


The first myth we need to debunk is that our phonetic alphabet represents all sounds. We only have twenty-six letters in our alphabet. However, in English, we have over 40 sounds. Depending on which linguist or educator you talk to, it ranges between 35-45 phonemes (sounds), which are influenced by an individual’s dialect (a specific regional accent that involves all aspects of language), education, training, and expertise. Depending on where you are from, you may disagree with the pronunciations in this article. This article’s pronunciation will be done based on General American English, a.k.a Standard American English. Historically, English dialect, education, training, and expertise have always influenced English spelling until the printing press was invented, and English became a bit more consistent with its spelling. Still, many of the origins of words remained the same despite the continued evolving of the way words are pronounced today.

The second myth we need to debunk is that all words are phonetically spelled. If that were the case, we would be spelling words such as ‘queen’ like ‘cween’ or ‘come’ like ‘cum’. We know that a good portion of English is phonetic. However, there is not an agreed-upon percentage. Depending on the linguist or educator you speak to, between 30%-70% of English is truly phonetic, and 30%-70% of English comes from other languages and historical influence. Can we safely assume the average, about 50% of English, is phonetically predictable? At the end of the day, it doesn’t matter because a skilled speller understands more than just phonology; they also have a deeper understanding of language, which combines phonology with morphology and etymology. Morphology is the study of the morphemes, which are the smallest unit of meaning in words.  Morphemes such as the prefix pre- meaning ‘before’ and the suffix -ly meaning ‘how’ are examples of morphemes in English.  Etymology is the study of the origin and history of words (Yule, 2019). A classic example of etymology may be a word we use in English originally borrowed from another language, such as the French word ‘Castle’ from Old North French or Norman French and ‘Chateau’ from Modern French (castle (n.), 2021).  Over time, English has evolved, and one of those evolutions has been the Schwa sound.

Spelling and I.Q.

Students have a lot of unnecessary pressure on things being spelled correctly. In our present day, you can see it happening in schools or social media when individuals curtly correct one another on which ‘there’ to use. Spelling has nothing to do with intelligence. However, if you don’t spell well, you may get labeled stupid or less intelligent than your peers. We must stop this misconception immediately, especially if you’re an educator, as this can be very damaging to a student’s self-esteem. Spelling has more to do with knowing the structure of language than intelligence. It’s comical to think about getting ‘bent-out-of-shape’ over the stress-inducing weekly spelling tests when we know historically; writers had many different spellings of simple English words like milk [mɪlk] (Writing Systems: Crash Course Linguistics #16 2021).


Schwa [ʃwa] was initially introduced and recognized in Western European languages by German linguists Johann Andreas Schmeller and Alexander John Ellis in the 19th century. The schwa sound was adopted from Hebrew’s phoneme schva [ʃva]. Hebrew adopted schva from Aramaic, which defined this sound as ‘even and equal,’ which is interesting considering Schwa is a mid-central vowel that has the appearance of an even opening between the tongue and roof of the mouth (see Figure 1). Although there is no exact date, we know that the Schwa was first used in English texts around 1890-1895. The schwa symbol is represented in I.P.A. (International Phonetic Alphabet) as the symbol [ə], a symbol that looks like the letter ‘e’ turned 180 degrees (Schwa 2021).


Why is the pronunciation challenging to teach?

If a teacher or educator is familiar with Schwa, it is challenging to teach because there is no letter representing this frequently occurring vowel sound. It simply does not exist in written language. Reading and literacy specialists who are not linguists will often associate the schwa sound with the similar wedge sound of [ʌ] or the short vowel sound /u/ like ‘upper’ to help students avoid omitting this vowel when writing (Yule, p.37). As any vowel can present as a schwa in an unstressed syllable (Mehlin, 2020) (see the section where is the Schwa?), this makes spelling the schwa sound especially difficult. The vowel sounds can be challenging, especially since we have only five vowel graphemes (letters), six if you’re counting y, representing the different vowel sounds in English. There is some debate about exactly how many spoken vowel sounds there are in English. According to linguists, between 12-14 vowel sounds can be produced, but are represented by a single or combination of graphemes in English (Phonetics 2 - Vowels: Crash Course Linguistics #9 202, Yule p.35). Schwa is the only vocalized vowel sound that is not represented by a specific grapheme(s).

What is the difference between [Ə] and [Ʌ]?

Let’s investigate briefly the difference between the Schwa [Ə] and the wedge sound [Ʌ] as these sounds are easily confused. As shown in Table 1, these are the significant characteristics of each sound that set them apart. In Figures 1 and 2, each figure is a screenshot of the rtMRI of the same person paused at the exact moment in phoneme production where you can see those physical differences of articulation when the sounds are produced. The yellow outline is drawn to emphasize the shape, notice in the schwa sound how ‘even’ and ‘equal’ the tongue is. Maybe the Aramaic’s ancient definition wasn’t so off. Not only is it clear to see how central the schwa sound is, but this proves that the schwa and wedge sounds are not the same sound. In Figure 3, you have the I.P.A. vowel chart that reflects the positions of the mouth when making the vowel sounds. Again, Schwa appears in the middle in black font to represent how it looks in the mouth as the most centered vowel sound. It can be easily assumed why this may be the most frequent vowel sound. Just look at the sound anatomy and how easy it seems to pronounce. It makes sense why this sound replaces other vowel sounds frequently in English.

Table 1: Outlined Characteristics (Schwa 2021, Wedge 2021)
Characteristics of Schwa [Ə] Characteristics of Wedge [Ʌ]
Occurs in unstressed Syllables Occurs in stressed syllables
Mid-central vowel or mid-central unrounded vowel – it occurs precisely in the middle of all vowel sounds (see Figure 1) Open-mid back unrounded vowel or low-mid back unrounded vowel
 (see Figure 2)
Sound is quick, fastSound can extend, last longer
           Figure 1: Schwa [Ə]  
Schwa [Ə]  (CSSTemplatesMarket, the rtMRI I.P.A. chart (John Esling))
       Figure 2: Wedge [Ʌ]
Wedge [Ʌ] (CSSTemplatesMarket, the rtMRI I.P.A. chart (John Esling))
Figure 3: I.P.A. Vowel Chart (Vowel diagram 2021)


Stressed, Secondary Stressed, and Unstressed Syllables

A stressedor accented syllable is a syllable that is longer, louder, or higher-pitched. Because it often has to do with vowel length when spoken, it identifies as the ‘longer’ syllable.  An unstressed or unaccented syllable is a syllable that is the shortest. There can be multiple unstressed syllables; unlike the stressed syllable, there is only one. In English, the Schwa shows up in unstressed syllables as it’s classified as a quick, fast sound.  It is sometimes difficult to recognize the stressed syllable in words, especially for struggling readers and spellers who have difficulty separating words into syllables. You can easily hear the stressed syllable if you ‘call out to the dog’ or ‘call out to your child.’ For example, if your dog’s name is Rover, and you call out to him, you can easily hear the stress in the syllable when calling the name RO-ver [ˈɹɔ.vɛʁ].  In fact, in two-syllable words, most of the time, the first syllable is accented (Barton, 2000). There can be what is considered secondary stress in three or more syllable wordswhere the syllable is longer than the unstressed syllable but shorter than the stressed syllable, which is often referred to as the primary stress.

An example of this would be the word emphasis [ˈɛɱfəsɪs] (Mehlin, 2020).  The bolded em [ˈɛɱ] is for the primary stress, the italicized sis [sɪs] is the secondary stress, and the pha [fə] is the unstressed syllable where the letter ‘a’ is going to the schwa sound.  It’s also apparent that a syllable having the greatest amount of letters doesn’t necessarily mean it’s accented, in the word ACrobat [ˈæk.ɹə.bæt], bat syllable has the most letters in a syllable yet AC [ˈæk] is the accented syllable. The multisyllabic words excluded from having a stressed syllable are compound words, two individual words put together that refer to one specific thing (Barton, 2000). Like sandbox and lipstick, words that do not have a specifically stressed syllable are considered equally stressed. Understanding stressed and unstressed syllables is the first step to helping us identify where Schwa shows up in words.

Semantics of Schwa

The branch of linguistics that discusses the meaning of words, phrases, and sentences are all included in the study of semantics (Yule, p.342). The semantics of Schwa is important to bring up because the meaning of a sentence, phrase, or word can change based on the stressed syllable in words. In the word ‘combine’ it can be said comBINE [kəmˈbaɪn] or COMbine [ˈkɑm.baɪn] depending on the context of the sentence and the meaning; depending on whether you comBINE [kəmˈbaɪn] substances or items together or you COMbine [ˈkɑm.baɪn] in unity or joined forces (Mehlin, 2020).  A suffix added to a word that is two syllables such as ‘able’ or ‘ity’ can completely change the meaning of a word and can move the Schwa or make it disappear entirely, such as the word LEgal [ˈliɡəl] which has a schwa when adding ‘ity’ to it. When adding the suffix ‘ity’, it changes the stress of the syllable and becomes leGALity [li.ˈgæl.ɪti] which no longer has the schwa sound and has a slightly different meaning when the suffix ‘ity’ is added (Barton, 2000).

Semantically, the context of a sentence can completely change based on where the stressed syllables are within a sentence. It is common for function words, which are the words used for grammatical purposes to convey better meaning but have little to no meaning on their own tend to go to Schwa, examples would be the, a, what, was, of, does, for, do, etc. (Mehlin, 2020).  These function words often go to Schwa within a sentence, such as I WENT TO the [ðə] STORE. However, we can notice in the sentence, ‘I didn’t see THE [ði] apple’ the is accented in this sentence due to the vowel being the initial sound of the proceeding word.  When we want to emphasize THE in the sentence, your intonation of the sentence can highlight the function words such as, “I went to THE [ði]  store,” said if you felt the need to defend where you went. Sometimes people will stress an article in a phrase like ‘A [e] dog,’ but it can become unstressed in a sentence, ‘I SAW a [ə] DOG..’  Although not everyone agrees, r-controlled vowels can show up as Schwa within a sentence, “Let’s go FOR [fɔɹ]it!” can turn into “LET’S GO fur [fə(ɹ)]IT!” (Mehlin, 2020). Notice these slight changes in meaning based on when syllables are stressed or unstressed when Schwa occurs. Where the Schwa shows up in phrases or sentences depends on the surrounding words and context.

Elision and Epenthesis of Schwa

There are a couple of interesting ways that Schwa can literally appear or disappear in words. Literally? How did you say that word in your head? Was it [ˈlɪtəɹəli] or the shorter version that includes omission of the first Schwa [ˈlɪtɹəli]? The process of leaving a sound out of the pronunciation of a word is elision (Yule, p.335). These are commonly called Syncope schwas. These are schwas that should be said in a multi-syllable word where a medial schwa is; however, it is deleted in casual conversation. A few common ones are chocolateà /choc/o/late[ˈt͡ʃɔk.ə.lɪt]à /choc/lit/ [ˈt͡ʃɔk.lɪt]; cameraà /cam/e/ra[ˈkæm.ə.ɹə]à /cam/ra [ˈkæm.ɹə]; or caramel, /car/a/mal/[ˈkɑɹ.ə.məl], car/mal [ˈkɑɹ.məl] (Mehlin, 2020). The same thing happens in reverse in a process called epenthesis, a sound change involving adding a sound to a word (Yule, p.335). A couple of examples of this is words like ath/ə/lete for athlete, burg/ə/lar for burglar, or real/ə/tor for realtor (Mehlin, 2020). Depending on how you enunciate words and the region you live, do you add or omit the schwa sound? If spelling this sound was not challenging enough, now we must worry about different dialects where individuals add or delete Schwa when speaking.

Locations of Schwa

Now that we have explored the more elusive ways that Schwa shows up let’s explore the places where Schwa almost always occurs. There are exceptions with any rule in English, so we’ll say ‘most of the time’ or ‘almost’ always.  A clever student will notice those exceptions and may find it interesting how the following patterns are where Schwa shows up the most. See Table 2 for a breakdown of these dependable locations of Schwa, broken into rules, definition, and example. Schwa is often taught in various explicit, systematic reading programs in different ways, but the overall principle of the following schwa rules is the same.

Table 2. Dependable Locations of Schwa    (Barton, 2000; Kleiber, 2011; Mehlin, 2020; Wilson, 1996)
Closed A or O goes to Schwa   Any closed syllable that is unstressed and has the letter ‘a’ or ‘o’ in it will go to Schwa. Cotton; combine; infant; apron; dragon
V-L at the end goes to Schwa Any vowel-L at the end of words that is unstressed goes to Schwa. Postal; tunnel; pencil; pistol
ANY Open-A goes to Schwa Any open syllable ‘a’ that is unstressed or at the end of words goes to Schwa. Banana; across; pacific; America; privacy
Consonant-LE Syllable Type Often L.E. sounds like [əl]. Pickle; tackle; stumble; marble
EN/IN at the end of words. Any Vowel-N ending can go to Schwa. The tongue often will clip that vowel shorter as it raises to the roof of the mouth to articulate the [n] sound closing the open airway production of any vowel sound. The schwa sound is much faster to produce to get to the [n] sound. Taken; cabin; spoken
Open Medial i/e making the schwa sound. When enunciated, you hear the open short [ɪ/ɛ] in the middle of the three or more syllable words. When said in everyday conversation, often the [ɪ/ɛ] turns to Schwa. Confident, elephant, dignity.
Scribal ‘O’ A theory scribes wanted to write the ‘o’ for the spelling of the schwa or wedge sounds when writing words so that the words traditionally spelled with a ‘u’ were not confused with letters like m, n, or v. Often, the scribal ‘o’ sounds like a schwa sound. Mother; another; come; wonder; love
Any TION/SION endings go to SchwaThe -ion ending in words, Pronounced shun for tion or sion or zhun for sion based on the vowel before it, these endings always go to Schwa.Elision; vacation; decision; fiction


Now that we have discussed Schwa and have a better understanding of stressed and unstressed syllables and where Schwa occurs, this can help us narrow down the many different schwa spellings in words. We already know how problematic schwas and vowels can be, now for a solution, we need S.O.S!

Simultaneous Oral Spelling

As mentioned before, we are not talking about the S.O.S. distress signal, but S.O.S known as simultaneous oral spelling. The origin of S.O.S was originated and was developed by master teachers Anna Gillingham and Bessie Stillman in 1954, based on the research done by neuroscientist Samuel Orton. Samuel Orton took a particular interest in the way we learn to read, write, and spell from a neurological perspective, especially students classified as Dyslexic.  This S.O.S method is commonly used by reading and literacy specialists today as a multisensory approach to spelling. Emily Gibbons from the Literacy Nest states that S.O.S “uses visual, auditory and kinesthetic learning modalities all at the same time during spelling dictation.” (Maestoo et al., 2018).  Listed below is an example of traditional simultaneous oral spelling steps and how they can help find the Schwa in words. 

Traditional S.O.S. Procedure

Simultaneous Oral Spelling

1.  LISTEN (Instructor says, “pat”) – critical student is watching mouth and facing instructor, preferably speaking to the student on the right side of them to take advantage of the ‘right ear advantage’ (Yule, p.193).

REPEAT (Student says, “pat”) – instructor makes sure not to proceed unless student articulated word correctly.

3. SLOW DOWN  - simple → complex tap syllables; what are the spelling rules?,  for bigger words or slow down and identify baseword, roots, morphemes, etc.


5. WRITE WHILE SAYING SOUNDS EX. for pat /p/ - /a/ - /t/ 


7. The student will then Proofread “pat” 

Outline created based on Orton-Gillingham S.O.S method by Jura Kool, Reading Specialist, A/AOGPE

Schwa Identifying S.O.S. Procedure – Example using the word ‘ENEMY’

 1. LISTEN (Instructor says, “enemy”) – critical student is watching mouth and facing instructor. preferably speaking to the student on the right side of them to take advantage of the ‘right ear advantage’ (Yule, p.193).


2. REPEAT (Student says, “enemy”) – The instructor makes sure not to proceed unless the student articulates correctly.

3. LISTEN FOR SPELLING (Instructor says, “enemy” again [ ɛn.ə.mi], then repeats word enunciating each syllable based on spelling saying it like “enemy”[ ɛn.ɛ.mi] with a slight hesitation between syllables, and then says it traditionally again, “enemy”[ɛn.ə.mi]) – instructor makes sure not to proceed unless student articulated word correctly and has identified this word having a schwa.

4.  SLOW DOWN  - simple → complex tap syllables; what are the spelling rules?, for bigger words or slow down and identify baseword, roots, morphemes, etc.

5.  STUDENT TAPS SYLLABLES EN-E-MY – instructor guides the student on hearing the schwa sound, then phonetic sounds based on spelling.

6.  WRITE WHILE SAYING SOUNDS EX. for EN-E-MY – if the student does not know whether to put a medial i/e in the middle based on the spelling rule medial i/e. The student will be guided to provide a space or a blank circle, or even a schwa symbol to help them get the word on paper and figure out the Schwa later.


7. DOUBLE-CHECK – the student will double-check by dividing the word into syllables to check their spelling. If schwa sound is not discovered already, a spell checker can be used to determine if the word enemy has a medial i/e in the middle syllable. Last resort if the student really could not identify Schwa.  The important thing is that the student can hear the Schwa when it occurs in the word. For example, the spell checker is used solely to identify the Schwa, for instance, en?my → enemy.


Proofread “Enemy” said phonetically and traditionally with schwa sound.

The Spelling Instruction Debate

The Limitations of S.O.S.

Some linguists argue that the difficulty with S.O.S. is that it forces us to follow the spell-by-sound method for English, which we know already is not all phonetic. Some would argue because we don’t hear the phonetic spelling sound in speech (we just hear Schwa), it’s too difficult to spell the correct vowel sounds when spelling. Kelli Sandman-Hurley, Ed.D, describes our English writing system as more morphophonemic (meaning that in English, a word’s morphemic structure will dictate how it is pronounced). She quoted Richard Venezky when he described English spelling as “the simple fact is that the present orthography is not merely a letter-to-sound system riddled with imperfections, but, instead a more complex and more regular relationship wherein phoneme and morpheme share leading roles (Venezkey, 1967, p.77).” (Sandman-Hurley, 2019).

As described earlier, a skilled reader and speller understand the components involved in spelling that involve more than just phonology but also morphology and etymology. An experienced practitioner who teaches reading will use guided discovery to incorporate word discovery when the student debates that they cannot hear those hard-to-spell vowel sounds as word formations become more complex. When this happens, it means the student has moved from the primary stages of spelling and is ready for a new technique to be added. The method that can be used with S.O.S. is called structured word inquiry or S.W.I. 

Structured Word Inquiry

S.W.I. or structured word inquiry uses matrices, word sums, morphology, and etymology of words to help with spelling. You can create your matrix by going to www.neilramsden.co.uk/spelling/matrix/temp/index.html, or you can do it on a piece of paper (Sandman-Hurley, 2019). Below is an example of a matrix for the word ‘mode,’ including word sums (See Figure 4).  Some S.W.I. practitioners swear by this approach as the only method that is the most effective for reading and spelling and will boldly state that no other process will produce strong spellers.

A Balanced Approach

To solve this overwhelming difficulty that Schwa creates regarding spelling vowel sounds, let us consider a balanced approach that works with an individual’s learning style. Whether S.O.S. or S.W.I. or a combination of the two helps educate others on English structure, that is the first step to producing stronger readers and spellers. We can’t argue that English is entirely phonetic, nor can we say that it isn’t phonetic at all.


In a world where everyone knew about Schwa, spelling vowels wouldn’t be so mysterious.  It would mean that words would be explicitly taught, and students would be required to recognize the Schwa in everyday language. As a result, the spelling of most words would significantly improve.  An individual would be able to use phonology, morphology, etymology, probability, common patterns, and better encoding strategies such as S.O.S. and S.W.I. to help them identify the correct spelling of the schwa sounds.


In a world where this is not possible yet, do not be distressed. It’s only a schwa. This common vowel sound can be taught as commonly as it is produced. It is very natural for us to use a schwa in spoken language, and reading words with a schwa in them is not difficult. If we apply these taught principles of Schwa, we might be less ‘stressed’ no pun intended, let’s be like Schwa - ‘unstressed.’ We can start by learning (or teaching if you are an educator) about stressed and unstressed syllables and the spelling patterns where Schwa is expected, why wait? As soon as we start learning about function words in sentence structure, we can begin to understand when Schwa occurs in ‘a’ and ‘the’ articles first and then move on to more complex words, phrases, and sentences. Applying these strategies will hopefully shed some light on this unseen vowel sound. Next time you hear the schwa sound, you will recognize it automatically. Knowing these strategies may help your spelling next time you recognize that frequently used Schwa.

Figure 4 –  (Ramsden, 2021)

  • Barton, S. E. (2000). The Barton Reading and Spelling System. Bright Solutions for Dyslexia.
  • Castle (n.). Index. (n.d.). https://www.etymonline.com/word/castle#etymonline_v_46634.
  • A child with his head in his hands. (n.d.). https://images.app.goo.gl/c8xyKAqotqaLB4Lu5.
  • CSSTemplatesMarket. (n.d.). the rtMRI I.P.A. chart (John Esling). span | the rtMRI I.P.A. chart (John Esling, 2015). https://sail.usc.edu/span/rtmri_ipa/je_2015.html.
  • Kleiber, M. (2011). In Specific Language Training (Vol. Intermediate Level, pp. 90–102). essay, V.C. Education Consulting.
  • Maestoo, H., Sorensen, C., & Lehmann, B. (2018, December 11). Using the S.O.S. Strategy. The Literacy Nest. https://www.theliteracynest.com/2014/07/using-sos-strategy.html.
  • Phonetics 2 - Vowels: Crash Course Linguistics #9. (2020). YouTube. https://youtu.be/qPTL5x0QW-Y.
  • Ramsden, N. (n.d.). Mini Matrix-Maker Results (demonstration only). Mini Matrix-Maker Results. http://www.neilramsden.co.uk/spelling/matrix/current/demo.html.
  • Sandman-Hurley, K. (2019). In Dyslexia and spelling: making sense of it all (pp. 29–30). essay, Jessica Kingsley Publishers.
  • What is Schwa? (2020). YouTube. https://youtu.be/1juGQ0R-Na0.
  • Wikimedia Foundation. (2021, June 9). Schwa. Wikipedia. https://en.wikipedia.org/w/index.php?title=Schwa&oldid=1027774115.
  • Wikimedia Foundation. (2021, March 15). Vowel diagram. Wikipedia. https://en.wikipedia.org/wiki/Vowel_diagram.
  • Wikimedia Foundation. (2021, May 5). Open-mid back unrounded vowel. Wikipedia. https://en.wikipedia.org/wiki/Open-mid_back_unrounded_vowel.
  • Wilson, B. A. (1996). Wilson reading system. Wilson Language Training.
  • Writing Systems: Crash Course Linguistics #16. (2021). YouTube. https://youtu.be/-sUUWyo4RZQ.
  • Yule, G. (2019). Chapter 5 Word Formation, Chapter 6 Morphology. In The Study of Language (7th ed., pp. 59–76). essay, Cambridge University Press.