8.147 USAGE NOTE

When you are giving advice, you sometimes want to tell someone what will happen if they do a particular thing. You do this by using an imperative clause, followed by 'and' and a clause containing a verb in a future tense.

For example, instead of saying 'If you go by train, you'll get there quicker', you can say 'Go by train and you'll get there quicker'.

When you are giving advice, a warning, or an order, you sometimes want to tell someone what will happen if they do not do what you say. You do this by using an imperative clause, followed by 'or' and a clause containing a verb in a future tense.

For example, instead of saying 'Go away! If you don't go away, I'll scream', you can say 'Go away, or I'll scream'.