Vowels Sit All Around The Consonant

Thai vowel spellings use signs in several positions relative to a syllable’s initial consonant. Some signs are combining marks above or below it; others are full-sized signs written before or after it. A spelling may combine signs in more than one position. These positions describe writing, not a rule that each sign is one separate vowel sound.

The Five Positions:

• After: Like the long 'a' in มา (maa, 'to come').
• Before: Like the 'ai' in ไป (bpai, 'to go'). The vowel sign is written first here, but its sound follows the initial consonant.
• Above: Like the 'i' in กิน (gin, 'to eat').
• Below: Like the 'u' in ดู (duu, 'to look').
• Surrounding: Some vowel spellings use multiple positions, like the 'ao' in เมา (mao, 'drunk'), or three positions like the 'ia' in เรียน (rian, 'to study').

Special Rules:
1. Consonant Clusters and Leading Consonants: In the following initial clusters and the example with leading ห, an above- or below-written vowel is placed at the second consonant: ปลี (bplee, 'banana blossom'), ครู (kruu, 'teacher'), or หมู (muu, 'pig'). An example with a tone mark at the second consonant is ใกล้ (glai, 'near'). In a true initial cluster, a preposed vowel sign is written before the whole cluster, rather than between its consonants (e.g., เปล - bpleh, 'hammock').
2. Implicit Vowels: Some syllables have a vowel sound without an explicit vowel sign. In นก (nok, 'bird'), the vowel is short 'o'; the explicit spelling โ-ะ is not written in this word. In สบาย (sa-baai, 'comfortable'), the first syllable has short 'a'. In ถนน (tha-non, 'road'), the first syllable has short 'a' and the second short 'o'. These are examples to recognize, not a rule that every closed syllable without a sign has 'o' or every open one has 'a'. Adjacent consonants may belong to different syllables, so word knowledge and context help identify the reading.
3. อ In Vowel Spellings: In the open-syllable spelling of long 'ue', the above-written part -ื is followed by อ, as in มือ (mue, 'hand'). Here อ belongs to the vowel spelling and is not a separate initial consonant sound. The letter อ also represents a vowel in spellings such as ขอ (kho, 'to ask for'). Its role depends on the complete spelling; do not treat every อ as silent or as the same vowel.
4. Phonemic Length: Thai distinguishes short and long vowel sounds, and a length difference can distinguish words. Learn the complete spelling and the word’s reading; the position of a sign alone does not determine length. Some conventional spellings have a reading that cannot be predicted by a simple short-versus-long shape rule.
5. Form-Changing and Reduced Vowels: Some vowel spellings have different written forms when a final consonant is present. The following are particular spelling patterns, not transformations to apply to every word. In a pattern for short 'a', written -ะ without a final consonant, the above-written mai han-a-kat (-ั) occurs with a final consonant, as in วัน (wan, 'day'). A closed-syllable spelling corresponding to short 'e' (เ-ะ) can use a ไม้ไต่คู้ (-็) as in เด็ก (dek, 'child'). A corresponding short 'ae' pattern (แ-ะ) uses mai tai khu in แข็ง (kaeng, 'hard'). In a closed-syllable 'ua' pattern corresponding to -ัว, the vowel is represented by ว, as in ขวด (kuuat, 'bottle'). One closed-syllable 'oe' pattern corresponding to เ-อ uses an above-written -ิ instead of อ (e.g., เดิน - doen, 'to walk'); a pattern before final ย does not write that อ (e.g., เคย - koey, 'used to'). Another conventional reading occurs in พร (phon, 'blessing'): it has a long vowel without a separate written vowel sign before final ร. Do not generalize this word into an automatic rule for every word ending in ร, or a claim that a written -อ was deleted. The special double-ร spelling (รร) has a short 'a' reading before the final consonant in ธรรม (tham, 'dharma'), and an 'an' reading in the first syllable of บรรทัด (ban-that, 'ruler'). Recognize the whole word and its syllable boundaries; this is not a rule for any two adjacent ร in any context.
6. Vertical Stacking: In spellings with an above-written vowel (like -ิ, -ี, -ึ, -ื) and a tone mark, the tone mark is displayed above the vowel sign (e.g., ดื่ม - duem, 'to drink', ที่ - thi, 'at/place'). The tone of a syllable depends on its consonant class, syllable type, vowel length, and any tone mark; a mark alone is not a fixed pitch label.