Although the concept of open and closed syllables is only rarely taught to learners of English, it is quite easy to grasp and knowing it can help you improve your pronunciation and spelling without much effort.
You are certainly acquainted with the concept of dividing words into syllables, like, for example, syl-la-ble. The general theory of syllables in English is somewhat involved, because syllables in the written form often don’t agree with syllables in pronunciation, but for our purposes it will suffice to say that a syllable is called open if its last letter (in the written form, not necessarily in pronunciation) is a vowel, and closed if it is a consonant. For example, “syl” is a closed syllable and “la” and “ble” are open syllables.
There are two factors that influence the pronunciation of vowels. First whether they are open/closed; secondly, the stress (whether it is stressed or not). There are three scenarios in which knowing this could be helpful:
1) If you know where the stress is and you know how to spell the word, you can usually guess the correct pronunciation of vowels; 2) if you know the correct pronunciation of a word, you can decide which syllables are open and which are closed, and this will help you to spell the word correctly; 3) if you know the ‘correct’ pronunciation and spelling, but you don’t know which syllable is stressed (which is quite common for learners), you can derive the stress position.
Pronunciation of standalone vowels
Let’s explain pronunciation of vowels in different cases, following the structure of my book about English pronunciation. Pronunciation is given in the IPA, as well as using an example in which the stressed syllable is bold and the vowel an example of which it is is underlined.
|Open||/eɪ/ take||/ə/ syllable|
|Closed||/æ/ cat||/ɪ/ spinach |
There are some exceptions to the table above—most notably, “ar” in a stressed syllable is usually pronounced with a long /ɑː/ (as in car). Also, pay attention to the fact that there can be more than one stress in a word. For example, “pineapple” is pronounced /ˈpaɪnˌæpl// with “a” being stressed as well, which causes it to be pronounced as /æ/ rather than /ɪ/.
|Open||/iː/ Peter||/ɪ/ enormous|
|Closed||/ɛ/ get||/ə/ moment|
The letter “e” plays a somewhat special role in English. Apart from its regular use (as in the table above), it is often used to complete a syllable in order to make the previous syllable open. For example, in the word “take”, the final “e” remains silent, but is used to make the word optically two-syllabic (i.e. ta-ke), thus changing the sound of a from /æ/ to /eɪ/.
|Open||/aj/ pine||/ɪ/ determine/ə/ terrible|
|Closed||/ɪ/ pit||/ɪ/ rapid|
The case of the letter “I” is somewhat more complex because it is generally hard to tell where the boundaries of syllables are, and this may be quite different also among various dialects of English. For example, “vitamin” is pronounced /ˈvɑɪtəmɪn/ in American English (and divided into syllables as vi-ta-min), whereas it is pronounced as /ˈvɪtəmɪn/ in British English (and divided as vit-a-min correspondingly).
|Open||/əʊ/ vote||/əʊ/ cello|
|Closed||/ɒ/ conscious||/ə/ Catholic|
There are two large classes of exceptions to the rules above. When “o” is followed by “r” in a stressed syllable, such as in “sport”, “chord”, “sore” etc., it is usually pronounced /ɔː/. In many words whose last letter is a stressed “o”, it is pronounced as /uː/, such as in “do”, “who”, “ado” etc.
|Open||/juː/ cute||/ju/ induce|
|Closed||/ʌ/ cup||/ə/ papyrus|
If “u” follows “r” or “l” in an open syllable, it is pronounced just /uː/, such as in “crude”, “prune”, “Luke”, “flu” etc. In American English, this happens also after other consonants, e.g. induce, duke, nuke. When “u” is followed by “r” in a closed syllable, it is usually pronounced /ɜː/ (UK; approximately like a long /ə/) or /ɜː/ (US; approximately like a long /r/ together with /ə/), e.g. curve, occur.
English pronunciation is very irregular, and there is often no other option than to get used to the correct pronunciation, as illogical as it may sometimes seem. However, in many cases, it is possible to derive the correct pronunciation of standalone vowels (i.e. vowels that do not form a part of a larger group of vowels) just by using the rules above.