Dave's ESL Cafe's Student Discussion Forums

[mings]

Hello.

Which tenses should I use in these sentences?

1. I have tidied my desk, but now it's in a mess again.
2. I tidied my desk, but now it's in a mess again.

Please help. Thanks.

[bud]

For all practical purposes, Mings, they have the same meaning. There is a difference in logic between the two, but in the end, the conveyed meaning is the same.

"I have tidied..." uses the present perfect. It concerns something that started in the past (tidying your desk) and continues to have relevance at present (it is still tidy, or at least you would expect that it is still tidy).

"I tidied..." uses the simple past. It concerns something that began and finished in the past. Even so, the implication is that you would expect your desk to still be tidy so soon (implied by the "but" clause) afterwards.

Sometimes you have a choice of using the simple past or the present perfect, with no real change in meaning. I don't know of any rules, though, of when that is true.

[mings]

Dear Bud,
Thank you for your explanation.
But in the second sentence, I feel something wrong with it. In a sentence we can use both simple past and simple present. Is it right?
Can you help to find out another best way to explain?

Many thanks.

[bud]

You're welcome, Mings.

The second sentence is fine. Many sentences use more than one verb tense. In this case, there are two clauses. The first is referring to the past and so must use a past tense. The second refers to the present, so it must use a present tense. There is no other way to do it that I know of.

The only time that I know of that we have to be concerned about keeping verb tenses consistent is in telling a story. (There are probably others that I'm not aware of.) You cannot start a story using the past tense, then swith to the present, then back to the past, etc. Even in that case, there might be reasons that certain sentences or clauses are in a different tense, but the sentences that futher the story line have to be consistent.

Ex.,

Many years ago, there was an old, quiet, single man who lived next door to us. (The story is being told in the simple past.) He never had visitors and rarely left his house. When he did, he never acknowledged anyone who crossed his path unless they spoke to him first. (The story line continues in the simple past.) He is no longer with us now, but through an odd coincidence, we became loyal friends... (The first clause is in the simple present - an aside to the main story to say that he is now dead.)

I hope that helps.

[mings]

Dear Bud,
I read you instruction with great satisfaction. I have no questions about the subject any more.
Thank you for your spending a lot of time on explaining to me.
Many thanks to you.

[bud]

Thank you, Mings!