1 believe
If you believe a person or believe what they say, you accept that what they say is true.
- He knew I didn't believe him.
- It all sounded so straightforward that I believed it myself.
- Don't believe a thing you read in that paper.
If you believe that something is the case, you think that it is the case.
- I believe some of those lakes are over a hundred feet deep.
- China makes you believe that everything is possible.
⚠️WARNING: Believe is not used in continuous tenses, even when you are talking about something which is happening now. You do not say, for example, 'I am believing you'. You say 'I believe you'.
- I believe you have to look at the positive side of things.
- I believe that these findings should be fairly presented to your readers.
2 don't believe
Instead of saying that you 'believe that something is not' the case, you usually say that you don't believe that it is the case.
- I just don't believe that Allen or you had anything to do with Styker's death.
3 'believe' before an object and a 'to' - infinitive
Believe can be followed by an object and a 'to' - infinitive. For example, instead of saying 'I believed that she was clever', you can say 'I believed her to be clever'. This is a rather formal use.
- I believed him to be right.
- He still believed himself to be a failure.
4 passive forms
Similarly, you can say either that it is believed that something is the case, or that something is believed to be the case. For example, you can say 'It is believed that the building is 700 years old' or 'The building is believed to be 700 years old'.
- It's believed that two prisoners have escaped.
- She is widely believed to have presidential aspirations of her own.
- The kidnappers are believed to be seeking a ransom.
5 believe so
If someone asks you if something is the case, you can say 'I believe so'.
- 'Can he be trusted?' - 'I believe so.'
⚠️ Note that when you are asked if something is the case, you do not say 'I believe it'.
6 believe in
If you believe in God or in such things as ghosts or Father Christmas, you think that they exist. If you believe in such things as miracles, you think that they happen.
- I don't believe in ghosts.
- Only 29 per cent of the population believe in a personal God.
If you believe in an idea or policy, you are in favour of it because you think it is good or right, or will have the desired result.
- Socialists believe in liberty.
- You don't believe in freedom.
