We couldn’t have asked for a clearer explanation, as Tim Bowen sheds light on these tricky phrasal verbs.
‘I bumped into Petra in the street the other day and she asked after you.’ If you ask after someone, you ask another person for news about them, enquiring about their health, for example.
To ask around means to ask several people for information or advice, as in ‘He asked me if I knew anyone who needed a part-time gardener. I asked around but no-one was interested’.
Ask can be used with various adverbial particles in the sense of ‘invite’, as in ‘They went to Venice last month and it was really nice of them to ask her along’. Invite along can be used in the same way, as in ‘I don’t mind you coming but I didn’t expect you to invite along half your family!’
To ask someone back can be used to invite someone to come to your home especially after you have both been somewhere together, as in ‘I’d invite you back but my parents are at home’, and to ask out means to invite someone to go somewhere because you want to start a romantic relationship with them, as in ‘He finally summoned up the courage to ask her out’.
Apart from its more common meaning of request, the phrasal verb ask for is used in a couple of idiomatic expression. If a person is asking for it, he or she is behaving in such a way that makes it likely that something unpleasant will happen, as in ‘Anyone who drives while they’re drunk is just asking for it’.
If you couldn’t ask for something, it means that you are emphasizing that it is so good that nothing could be better, as in ‘We couldn’t have asked for better weather’.