I don’t know - definition and synonyms

  1. 1
    used for saying that you are not certain about something
    I don’t know whether:

    I don’t know whether economic issues were discussed specifically.

  2. 2
    used for saying that you do not completely agree

    ‘It’ll be boring.’ ‘Oh I don’t know. It might be fun.’

    I don’t know that:

    I don’t know that we need to discuss this.

  3. 3
    used when you are giving your opinion and want to find out what someone else thinks

    I don’t know about you, but I’m starving.

  4. 4
    used for criticizing someone
    I don’t know what/how/why etc:

    I don’t know what they were thinking of.

    I don’t know how he could be so cruel.

See also main entry: know