The usage of future perfect tense

English as a Second Language English Vocabulary, Grammar and Idioms
21

Hi Duc

The main difference between those two sentences is that one looks at the future and one looks at the past.

He will wash up (before he goes to bed). ‘Before he goes to bed’ basically tells you when in the future he will wash up. It is not a precise statement of time such as ‘at 10 pm this evening’, nevertheless that clause refers to a time (“when”) in the future.

He washed up (before he went to bed). ‘Before he went to bed’ basically tells you when he washed up in the past. Just as in the future usage, it is not a precise statement of time such as ‘at 10 pm yesterday’. Nevertheless that clause refers to an approximate past time.
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22

So the sentence ‘‘He washed up before he went to bed’’ is grammatically true,isn’t it ? And does it sound good to you?

23

Hi Duc

Yes, that sentence is perfectly grammatical. Although I personally don’t use the phrase ‘wash up’ very often, the sentence still sounds fine to me.
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