Mary has cooked dinner means that she cooked dinner awhile ago and it's now ready to be eaten. Yes, that's true. It's one of the usages of the Present Perfect. Something happened in the past but the outcome is still relevant in the

What about: Has she really done what is best for the kids. Is this sentence correct? Yes, of course! Actually, it's much better than the original "Has she really done what was best for the kids", as 'is' indicates that

No, they're different. The difference is that of between present perfect and past perfect . It's no use asking about the difference between some sentences all the time without first learning the difference between those two tenses. That

You have changed the tenses properly, but have is a non-progressive verb when it carries the meaning of an obligation, so it is not used in the progressive tenses. Let's use a verb that can be used in the progressive tenses. Present: I call

THe Past perfect simple is had + past participle. I/we/they/you/he/she/it had (=I'd/ he'd etc) gone/seen/finished. etc. Have done is present perfect/ had done is past perfect. Hope that helps.

Yes, I used the present perfect instead of the past perfect. I had had my pc reformatted before I bought a new monitor. (but the simple past will do just fine here)

so what and how is past perfect used? Have you ever had your pc reformatted? Yes, I've had my pc reformatted (before). I'm sorry but you're mixing the past perfect with the present perfect here.

I've had my pc reformatted = present perfect I had my pc reformatted = past simple I had had my pc reformatted = past perfect These sentences use the structure 'have something done' that is have someone to do certain things for you .

I can't get it anywhere - so difficult, why we should say:"has/have been" when we haven't any point of time? I suggest that you write some sentences in these two tenses and post them here so that we can see where the problems

Use the present perfect aspect ( have/has + -ed verb form ) for events that continue from the past to the present, for past repeated events that are presumed to repeat into the future, and for past events that otherwise relate to the present in