После союзов: till, untill, before, as soon as, when, after, if, ...

Vasy

I shall be here till five o'clock.Let us wait until the rain stops.If you do something as soon as possible, you do it at the first possible opportunity.By the time she was two, she could whistle the melody of songs she heard on the radio. I suppose if she had asked him for a brief history of himself, he would have been well prepared to share