Like English, vowel sounds in Thai can have multiple spellings using different vowel letter patterns.
For example: "meat" and "meet" produce the same vowel sound, but are spelt with different vowel letters.
"Meat" matches the "◌ea◌" pattern, and "meet" matches the "◌ee◌" pattern.

The patterns and word counts are derived from the syllabic spellings in the dictionary of this website.
There are slight variations in exact patterns used, depending on the source.
Please note that vowel length can change depending on tone mark in some vowels.