คือ

Explanation

The core pattern is A คือ B. The information after คือ identifies A by giving its name, identity, definition, or exact content. What follows can be a noun or an entire clause, as in ปัญหาคือเงินไม่พอ, “The problem is that there isn't enough money.” It also introduces a clarification, example, or list, functioning like “namely,” “that is,” or “as follows.” In conversation, คือว่า or a hesitant คือ... can lead into a request, refusal, correction, or explanation. In that use, it works more like “the thing is...” or “well...” than the identifying verb.

Usage

It is very common when asking what something is, introducing someone, defining a term, or stating the exact answer or main issue. Lessons, presentations, and explanatory writing also use it before clarifications and lists. In everyday speech, it often introduces a request, refusal, or personal explanation.

Caution

คือ is not a general-purpose equivalent of “is” or “am.” Use เป็น for occupations, status, and categories: เขาเป็นครู means “He is a teacher.” เขาคือครู instead strongly identifies him as the particular teacher in question. Do not insert คือ before an adjective simply because English uses “be”; เขาสวย directly means “She is beautiful.” คือ does not make a sentence polite—sentence-final ครับ or ค่ะ can do that. Repeating conversational คือ too often may sound like an excessive verbal filler.

1 be (in an identifying or defining sense) synonyms

• หมายถึง

  หมายถึง explicitly means “mean” or “refer to,” especially when explaining words or statements. คือ has a broader role, equating or identifying A with B.

• เป็น

  pen be

  เป็น normally describes a person's occupation, status, category, or condition. คือ instead identifies a specific name, identity, definition, or answer.

2 namely synonyms

• กล่าวคือ

  กล่าวคือ is a somewhat formal, written-style equivalent of “that is to say.” คือ is shorter and common in both conversation and writing.

• ได้แก่

  ได้แก่ is especially common before a list of members or examples. คือ can introduce a list too, but also works more broadly before a single answer or clarification.