how long adjective 2adverb 1 adjective2 •Used literally: what length.How long is that piece of string?I don't know how long the Amazon River is. •Used literally: what duration.How long are you here for? ~ Until the end of next month.How long have you already been here (for)? ~ Since last Friday adverb1 •Used literally: for what duration.How long have you lived in Chicago?He won't tell me how long he is going to stay.
