Below are steps to help you identify the form-changing vowels in Thai:

1️⃣ Step 1: Identify the Vowel

Look at the vowel in its “full (normal) form“ first (i.e., –ะ /-a/, เ–ะ /-e/, เเ–ะ /-ae/, เ–อ /-eeu/).  

2️⃣ Step 2: Check for a Final Consonant  

If the syllable ends with a consonant, the vowel may change:  

– “–ะ” → “◌ั ” (e.g., “กัน” /gan/ instead of “กะน”).  

– ” เ–ะ ” → ” เ–็ ” (e.g., “เด็ก” /dèk/ instead of  “เดะก”).  

3️⃣ Step 3: Adjust the Vowel Position  

Some vowels change its form, or a part of its form, and move above the consonant:  

🚨Vowel “–ะ” becomes a small mark above “◌ั ” the initial consonant.

        For example:

• ก + –ะ + น becomes “กัน” /gan/
• จ + –ะ + ด becomes “จัด” /jàd/
• ป + –ะ + ก becomes “ปัก” /bpàk/

🚨Vowel ” เ–ะ ” becomes a small mark above ” เ–็ ” the initial consonant.

        For example:

• ด + เ–ะ + ก becomes “เด็ก” /dèk/
• จ + เ–ะ + ด becomes “เจ็ด” /jèd/
• ม + เ–ะ + ด becomes “เม็ด” /méd/ 

🚨Vowel ” แ–ะ ” becomes a small mark above ” แ–็ ” the initial consonant.

        For example:

• ข + แ–ะ + ง becomes “แข็ง” /kǎeng/
• ฮ + แ–ะ + ก becomes “แฮ็ก” /háek/
• ม + แ–ะ + ก becomes “แม็ก” /máek/  

🚨Vowel ” เ–อ ” becomes a small mark above ” เ–ิ ” the initial consonant.

📌 NOTE: This applies to other ending consonants, except for the consonat “ย”

For example:

• ด + เ–อ + น becomes “เดิน” /deeun/
• ช + เ–อ + ญ becomes “เชิญ” /cheeun/
• ก + เ–อ + ด becomes “เกิด” /gèeud/

4️⃣ Step 4: Practice with Real Words  

Here is how you can practice writing and reading Thai words with the form-changing vowels:

🇹🇭 Start with Simple Words – Write each word multiple times and say it out loud as you write.

🇹🇭 Focus on One Vowel at a Time – You can work on one vowel first,  such as the vowel “-ะ” and find the words that use it. You will see how it changes based on the ending consonant it pairs with.

🇹🇭 Highlight the Vowels – When reading words, mark the vowels with a colored pencil or highlighter to visually focus on them while you learn how they interact with consonants.

🇹🇭 Use Vocabulary Lists – Take beginner-friendly word lists and look for those including form-changing vowels. Practice writing each word several times to get yourself familiar with their patterns.

🇹🇭 Practice with Sound – Listen to how the words are pronounced in apps or videos. Then write down what you hear to check if your written vowels match the correct spelling of the words.