 Re: American English : telling the time
'30 till' would technically be OK in your example but it's not natural. Naturally I would say, 'I have to go at half-past.'
'XX till' usually isn't used until about 20 minutes till the hour, but yes, if the hour is know you don't need it. For example, you are in a meeting and the meeting started at 2:00. If you need to wrap up the meeting by 2:50, you could say, 'We need to finish up by 10 till.'
(I'm American.) |