How and where to use do it, do this and do that?


Mark cuts the grass every day. He does it after lunch.

You need to learn three new words every day. If you do this for six months, you will have a large vocabulary.

Usain Bolt ran 100 meters in under 10 seconds. Few people are able to do that!



Practical English Usage says

1 do so

The expression do so can be used to avoid repeating a verb and its object or complement. It is usually rather formal.

 'Put the car away, please.' 'I've already done so.'

 Eventually she divorced Joshua. It was a pity she had not done so earlier.

 He told me to get out, and I did so quietly as possible.

2 do so and do it/that

 Do it and do that can be used instead of do so.

 I promised to get the tickets, and I will do so/it as soon as possible.

 She rode a camel: she had never done so/that before.

We use do so mainly to refer to the same action, with the same subject, that was mentioned before. In other cases we prefer do it/that or do alone.

 I haven't got time to get the tickets. Who's going to do it? (NOT ... Who's going to do so?)

 'I rode a camel in Morocco.' "I'd love to do that." (NOT ... to do so.)

 I always eat peas with honey. My wife never does. (NOT... My wife never does son.)

3 Do so/it/that: deliberate actions.

Do so/it/that are mainly used to refer to deliberate dynamic actions. We do not usually use these expressions to replace verbs like fall, lose, like, remember, think, own, which refer to involuntary actions or states.

 I like the saxophone, and I always have (done). (AmE... and I always have.)

 (NOT... and I have always done so/it/that.)

 She lost her money. I wasn't surprised that she did.

 (NOT... that she did so/it/that.)

 I think Jake's wrong. I did when he first spoke to me.

 (NOT... I did so/it/that when...)

4. other verbs

Note that so, it and that are not normally used in this way after auxiliary verbs. It is not possible in standard English to say I can so, She was it or I have that.

You might want to buy Practical English Usage by Michael Swan.

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