If you watch Thai dramas, there’s one word you’ll hear over and over again.

That word is jai (ใจ).

What does jai mean?

Jai literally translates to “heart”, “mind”, or “spirit”.

While we have the word hŭa-jai (หัวใจ) for the physical organ pumping blood in your chest, the word jai is used to describe feelings, emotions, and personality traits.

To speak natural Thai, you can’t ignore this word.

In English, we might say someone is “kind”, “impatient”, or “sad”. In Thai, we almost always use the word “heart” to describe these states. We say someone has a “good heart” (kind), a “hot heart” (impatient), or a “broken/spoiled heart” (sad).

Understanding these words is the key to understanding the Thai people themselves.

Keep reading and I’ll explain the most common and useful “heart words” you need to know.

Positive personality traits using ‘jai’

When you want to compliment someone or describe a good person, you will likely use one of these words.

Notice that for personality traits, the word jai usually comes first, followed by an adjective.

Jai dee (Kind)

This is the first phrase most students learn. Dee (ดี) means good. So, jai dee literally means “good heart”.

We use this to describe someone who is kind, nice, or good-natured.

Jai yen (Calm / Cool-headed)

Yen (เย็น) means cool (temperature).

If you are jai yen, you have a “cool heart”. This means you don’t get angry easily. You are calm, relaxed, and patient. This is a very highly respected trait in Thai culture.

Jai gwaang (Generous)

Gwaang (กว้าง) means wide or broad.

Someone who is jai gwaang has a “wide heart”. They are generous, open-minded, and willing to share what they have with others.

Nam jai (Kindness / Spirit)

This is a noun, not an adjective. Nam (น้ำ) means water. So this is “water from the heart”.

Nam jai is a very famous Thai concept. It represents genuine kindness, hospitality, and the willingness to help others without being asked.

Negative personality traits using ‘jai’

Just like we have “cool hearts”, we also have “hot hearts”. Here are the words used to describe negative behaviors.

Jai ron (Impatient / Hot-tempered)

Ron (ร้อน) means hot.

Someone who is jai ron has a “hot heart”. They are impatient, impulsive, or they get angry very quickly. This is the opposite of jai yen.

Jai dam (Mean / Cruel)

Dam (ดำ) means black.

A “black heart” is exactly what it sounds like. It describes someone who lacks compassion, is mean, selfish, or cruel. If you refuse to help a friend in need, they might call you jai dam.

Jai kaep (Narrow-minded / Stingy)

Kaep (แคบ) means narrow.

This is the opposite of jai gwaang (generous). Someone who is jai kâep is narrow-minded or stingy with their money or feelings.

Expressing emotions and feelings

While the words above describe personality (who you are), the words below describe emotions (how you feel right now).

For feelings, the grammar often flips. Usually, the adjective comes first, and jai comes second.

Here is a list of the most common emotional heart words:

Examples in context:

Dee jai (Happy/Glad) Note: Mii kwaam sùk is “happy” in a general life sense, but dee jai is usually a reaction to good news or an event.

Sia jai (Sad/Sorry) We use this when we are sad, but also to apologize (literally “I feel bad/sad about this”).

Tok jai (Shocked/Startled) Use this when someone jumps out and scares you, or you hear sudden bad news.

Greng jai (Considerate) This is a unique Thai concept. It describes the feeling of not wanting to bother or inconvenience someone else.

How to use ‘jai’ words in a sentence

Using these words is actually quite simple compared to English. You don’t need complex verb conjugations.

1. Subject + Adjective (Heart Word)

In Thai, adjectives function very similarly to verbs. You don’t always need the verb “to be” (bpen or kue).

2. Subject + Feeling (Heart Word)

3. Describing someone else

If you want to say someone is a “kind person”, you use the structure: Kon (Person) + tîi (that/who) + jai word.

Regional variations and summary

The concept of jai is universal across all of Thailand.

Whether you are in Bangkok, Chiang Mai, or Phuket, these words are used every day.

However, if you travel to the Isan region (Northeast Thailand), you might hear the local dialect. In Isan, the word jai is still used, but the pronunciation might change slightly, and the surrounding words will change.

For example, “happy” in Standard Thai is dee jai, but in Isan, you might hear muan (fun/enjoyable) used more often to describe the atmosphere.

But generally, jai is the core of Thai emotion regardless of the region.

A few tips to take note of:

• Don’t memorize them as a list. Try to learn them in pairs (Hot/Cold, Good/Black, Wide/Narrow).
• Listen for context. Thais talk about their hearts constantly. When you watch a movie, listen for “jai”.
• Use them yourself. Telling a Thai person they have “nam jai” (kindness) is one of the best compliments you can give.

Learning these heart words allows you to stop translating from English and start feeling the language like a Thai person.

Do you have a favorite Thai “heart” word?