'Can', 'could', 'be able to', 'manage to' Present tenses Present perfect continuous 'Like' for preference and description Adverbs of frequency 'Have to' and 'must' The past simple tense ...
Whether teaching or learning the present perfect, it is often useful to present the two verb aspects in a contrastive way. Compare the following: 'Dick Francis has been writing novels since 1957. In ...