A syllable is a unit of pronunciation uttered without interruption,^[1] loosely, a single sound.^[2] All words are made from at least one syllable.

Monosyllables are words that have only one vowel sound; polysyllables have more than one. If a syllable ends with a consonant, it is called a closed syllable. If a syllable ends with a vowel, it is called an open syllable. Patterns of syllables can be shown with C and V (C for 'consonant', V for 'vowel'). Closed syllables are often shown as CVC (such as got), and open syllables as CV (such as go). Some languages like English have many kinds of closed syllables. Other languages, like Japanese, have few kinds of closed syllables. Other languages still, like Hawaiian and Swahili, have no closed syllables.

Notice that the consonant (C) and vowel (V) notation does NOT match the letters of English spelling in a one-to-one relationship (e.g. 'th' is one sound), but rather individual sounds.

There are many words in English that have only one syllable.

IPA has been added in slashes.

• He /hi/ (CV) - open
• The /ði/ (CV) - open
• Like /lɑɪk/ (CVC) - closed
• Run /ɹʌn/ (CVC) - closed
• Cat /kæt/ (CVC) - closed
• House /hoʊs/ (CVC) - closed
• It (VC) /ɪt/ - closed
• On (VC) /ɑn/ - closed

However, in several languages, such as English, syllables can have consonant clusters (having multiple consonants next to each other), which easily allow for words to have much more complicated syllables, such as:

• Crow /cɹow/ (CCV) - open
• Through /θruw/ (CCV) - open
• Spray /spɹej/ (CCCV) - open
• Ports /pɔɹts/ (CVCCC) - closed
• Sports /spɔɹts/ (CCVCCC) - closed
• Trip /tɹɪp/ (CCVC) - closed
• Dent /dεnt/ (CVCC) - closed
• Plant /plænt/ (CCVCC) - closed
• Sprint /spɹɪnt/ (CCCVCC) - closed
• Splints /splɪnts/ (CCCVCCC) - closed
• Strengths /stɹeŋθs/ (CCCVCCC) - closed
• Angsts /eɪŋsts/ (VCCCC) - closed

There are many more words that have two or more syllables.

• Basket /bæs.kεt/ (2 Bas-ket; CVC-CVC)
• Doctor /dɔc.tɔr/ (2 Doc-tor; CVC-CVC)
• Happy /ha.pi/ (2 Ha-ppy; CV-CV)
• Friendly /frεnd.li/ (2 Friend-ly; CCVCC-CV)
• Greenland /grin.lænd/ (2 Green-land; CCVC-CVCC)
• Computer /cəm.pju.tər/ (3 Com-pu-ter; CVC-CCV-CVC) [-pu- is pronounced "pyuu' or CCV]
• Merciful /mər.ci.fəl/ (3 Mer-ci-ful; CVC-CV-CVC)
• Pronunciation /prə.nən.ci.eɪ.ʃən/ (5 Pro-nun-ci-a-tion; CCV-CVC-CV-V-CVC)

Some languages do not use an alphabet with letters. Instead, each sign may stand for a syllable. For example: Japanese can be written using Kana. A writing system based on syllables is called a syllabary. Since words in languages like English can have many different complex syllables (well over 10,000 can be produced in English),^[3] writing such languages using a syllabary would be completely impractical, thus alphabets are much better suited to write languages with complex syllable structures. However, since words in Japanese can be made with just a few simple syllables (around 90), writing such languages are well suited for the type of language.