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.
(thinking for a few seconds)
Common error: Don’t use “think to” for “considering.”