ADV. firmly, really, seriously (only used with negatives), sincerely He firmly believed that he was right. No one seriously believes that this war will happen. | mistakenly
VERB + BELIEVE can't/cannot, could not I couldn't believe what I was hearing. | be hard to It's hard to believe that this campaign has been going on for ten years. | give sb to The boss gave me to believe that we would all get a pay rise. | have reason to We have reason to believe that the escaped prisoner may be hiding in this house. | be inclined to I'm inclined to believe you. | lead sb to The advertisement led us to believe that all prices had been cut.
PHRASES can/could hardly/scarcely believe sth, not believe a word of sth I didn't believe a word of what he said.