think about / think of

The two most common prepositions used after the verb “think” are “about” and “of.” They are very similar, but there is a small difference.

Usually when you think of something, it is a brief moment – just a few seconds. It is also used for opinions. When you think about something, you are considering it for a longer time – like a few minutes or more.

  • Every time I hear this song, I think of my mother.

    (thinking for a few seconds)

  • What do you think of my new haircut?


  • I’m thinking about moving to a different city.


  • I still get angry when I think about all the rude things my sister said to me. (thinking for a few minutes or more)

    Common error: Don’t use “think to” for “considering.”

  • I’m thinking to do an intensive English course in Canada.
  • I’m thinking about doing an intensive English course in Canada.