Sinhala has so-called prenasalized consonants, or 'half nasal' consonants. A short homorganic nasal occurs before a voiced stop, it is shorter than a sequence of nasal plus stop. The nasal is syllabified with the onset of the following syllable, which means that the moraic weight of the preceding syllable is left unchanged. For example, tam̆ba 'copper' contrasts with tamba 'boil'.
| Labial | Dental/ Alveolar |
Retroflex | Palatal | Velar | Glottal | ||
|---|---|---|---|---|---|---|---|
| Nasal | m | n | ŋ | ||||
| Stop | voiceless | p | t | ʈ | tʃ | k | |
| voiced | b | d | ɖ | dʒ | ɡ | ||
| prenasalised | ᵐb | ⁿd | ᶯɖ | ᵑɡ | |||
| Fricative | (f, ɸ) | s | (ʃ) | x | h | ||
| Trill | ʙ | r | |||||
| Approximant | ʋ | l | j | ɰ | |||
/f~ɸ/ and /ʃ/ are restricted to loans, typically English or Sanskrit. They are commonly replaced by /p/ and /s/ respectively in colloquial speech. Some speakers use the voiceless labiodental fricative [f], as in English, and some use the voiceless bilabial fricative [ɸ] due to its similarity to the native voiceless bilabial stop /p/.
| Front | Central | Back | ||||
|---|---|---|---|---|---|---|
| short | long | short | long | short | long | |
| Close | i | iː | ɨ | ɨː | u | uː |
| Mid | e | eː | ə | (əː) | o | oː |
| Open | æ | æː | a | aː | ɒ | ɒː |
Long /əː/ is restricted to English loans. /a/ and /ə/ are allophones in Sinhala and contrast with each other in stressed and unstressed syllables respectively. In writing, /a/ and /ə/ are both spelt without a vowel sign attached to the consonant letter, so the patterns of stress in the language must be used to determine the correct pronunciation. Most Sinhala syllables are of the form CV. The first syllable of each word is stressed, with the exception of the verb කරනවා /kərənəˈwaː/ ("to do") and all of its infected forms where the first syllable is unstressed. Syllables using long vowels are always stressed. The remainder of the syllables are unstressed if they use a short vowel, unless they are immediately followed by one of: a CCV syllable, final /j(i)/ (-යි), final /wu/ (-වු), or a final consonant without a following vowel. The sound /ha/ is always stressed in nouns, adjectives, and adverbs, and so is not pronounced /hə/ except in the word හතලිහ /ˈhat̪əlihə/ ("forty"), where the initial /ha/ is stressed and the final /hə/ is unstressed.