Yes–No Questions with ไหม

Thai forms a neutral yes–no question by keeping the ordinary statement order and adding ไหม at the end of the proposition. วันนี้ร้านเปิด means “the shop is open today”; วันนี้ร้านเปิดไหมคะ asks “Is the shop open today?” There is no subject–auxiliary inversion and no added equivalent of English do.

The question particle comes before a final polite particle: ไหมครับ for a male speaker and ไหมคะ for a female speaker's polite question. The female question form is คะ, not statement ค่ะ. Although ไหม and negator ไม่ are written similarly and both have RTGS mai, they are different words with different tones and positions.

Keep statement order and add ไหม

Start with a complete Thai proposition, whether its predicate expresses an action, state, possession, or ability. Add ไหม after that proposition. The subject can remain present or be omitted when conversation makes it recoverable.

English switches between is, do, and can at the front. Thai leaves เปิด, กิน, and ได้ where they belong in the predicate. ไหม signals that the speaker is asking the listener to choose between positive and negative possibilities.

ไหม follows the whole proposition

Time phrases, objects, locations, and complements remain inside the proposition, before ไหม. The particle does not replace a missing tense auxiliary.

The predicates do not change in the past or future examples. เมื่อวาน anchors a past question, while พรุ่งนี้ and จะ establish a prospective one. Removing จะ can still leave future reference when tomorrow is explicit: พรุ่งนี้เข้าประชุมไหมคะ is natural in conversation.

Answer with the relevant predicate

Thai has ใช่ and ไม่ใช่, but they are not universal equivalents of English yes and no. The most informative short answer repeats the predicate or modal from the question.

For มี…ไหม, answer มี/ไม่มี. For ไป…ไหม, answer ไป/ไม่ไป. For ได้ไหม, answer ได้/ไม่ได้. Use ใช่/ไม่ใช่ when the question itself asks for identification or confirmation with ใช่ไหม, not simply because English would use yes/no.

The basic negative-predicate pattern explains why ไม่ precedes the repeated action or property in a negative answer.

Information seeking, confirmation, and repair

Plain ไหม most naturally asks an open polar question: the speaker does not grammatically present either answer as already established. For confirmation, Thai commonly adds ใช่ไหม after the proposition. That larger frame still ends in ไหม, but ใช่ signals “is that right?” rather than a completely open request.

Plain ไหม is not a universal ending for every English yes–no question. In particular, standard Thai normally avoids attaching neutral ไหม directly to an already negative predicate. Negative questions and alternative forms with หรือเปล่า have their own discourse conditions; first master the positive-predicate frame taught here.

The same shape can repair uncertain hearing: เมื่อกี้บอกว่าห้องสามใช่ไหมคะ “You said room three just now, right?” The prior utterance supplies the proposition being checked. Do not assume all final question expressions are interchangeable: neutral ไหม, confirmation ใช่ไหม, and alternatives built with หรือ have different discourse jobs.

Politeness and spelling

Standard writing uses ไหม. The spelling มั้ย represents a widespread conversational pronunciation and is frequent in texting and informal dialogue, but it is (informal); this guide uses standard ไหม in neutral examples. RTGS writes both without tone marks as mai, so the Thai script and sentence position are essential.

The polite particle follows the question particle:

• male speaker: …ไหมครับ
• female speaker: …ไหมคะ

Female ค่ะ marks statements and answers, as in ไม่ไปค่ะ. Female คะ marks questions or attention calls, as in ไปไหมคะ. A question mark may appear in modern writing, but ไหม and context already mark the clause as interrogative; punctuation does not replace the particle in these examples.

Ordinary-polite dialogue

A hotel guest asks about breakfast.

The final answer repeats the modal ต้อง under negation. ไม่ใช่ครับ would answer the wrong kind of question, and bare ไม่ครับ would be less informative.

Common Mistakes

1. Inverting subject and predicate like English

2. Adding ทำ as English do-support

3. Putting ไหม before the predicate

4. Using female statement ค่ะ after a question

5. Answering an action question with ไม่ใช่

Key Takeaways

• Keep normal statement order and place ไหม after the full proposition.
• Put polite ครับ/คะ after ไหม; female statement ค่ะ does not belong there.
• Time expressions and aspect locate the event; ไหม is not tense morphology.
• Answer by repeating the relevant predicate or modal rather than forcing universal ใช่/ไม่ใช่.
• Use standard ไหม in neutral writing; มั้ย is a widespread informal spelling.