Explanations

1. The preposition for is used to say how long an activity continues. It refers to the length of time (for an hour, for ages).

2. The prepositions from ... to ... also tell us how long an activity continues. They refer to the start and the finish. (You could also say from ... until / till ...) 3. The preposition until (or till) refers to the end point

(until 4.30).

4. Another way to talk about the length of time is to use the verb spend (+ length of time) + verb + -ing.

5. The verb take can be used to say how much time you need to do something. 6. Here, the preposition in indicates how much time is needed to do something. It refers to the length of

time (in an hour).

7. The preposition by has a similar meaning, but it refers to the end point (by six = at or before six). 8. More examples of in and

by with time expressions.