had transformed

[Maybo]

This time, when the magical smoke disappeared, the Genie had transformed into a regular-sized human with a smaller hat.(Aladdin by Elizabeth Rudnick)

Why "had transformed" is used but not "has transformed"?
I know the sentence is talking about the past but doesn't "has transformed" already mean the transformation happened before "disappeared"?

 

[emsr2d2]

Yes, and that's exactly what happened. The transformation must have happened before the smoke disappeared. If it hadn't, the smoke would have cleared and then the audience would have seen the transformation in action.

 

[Maybo]

Yes, and that's exactly what happened. The transformation must have happened before the smoke disappeared. If it hadn't, the smoke would have cleared and then the audience would have seen the transformation in action.

Then why the original one is "had transformed"?

 

[emsr2d2]

I believe the "this time" is a time in the past.

 

[Maybo]

I believe the "this time" is a time in the past.

I know, but why not, "This time, when the magical smoke disappeared, the Genie has transformed into a regular-sized human with a smaller hat."?

Can I use it?
For example: When I arrived, he has left.
Isn't the sentence also referring about the past? What's the different when I use "had left"?

 

[Charlie Bernstein]

I know, but why not, "This time, when the magical smoke disappeared, the Genie has transformed into a regular-sized human with a smaller hat."?

Because it's in the past.

Can I use it?

No.

For example: When I arrived, he had left.

Depending on what you mean, you could also say:

- By the time I arrived, he had left.
- When I arrived, he was already gone.

Isn't the sentence also referring to the past?

Yes. So use had.

What's the difference when I use "had left"?

The difference is that had left is correct.

It's like life. It's usually a good idea to leave the past in the past.

 

[Maybo]

It's like life. It's usually a good idea to leave the past in the past.

Can I use present perfect tense in the following situation?

Please make sure you has turned on the computer when you use the projector.

 

[emsr2d2]

You can use the present perfect there but "you has" is never correct. Try again.

 

[Maybo]

Please make sure you have turned on the computer when you use the projector.

 

[emsr2d2]

Going back to the original question, if you were commenting on the magic show while you were watching it, you could say "Wow! The genie has transformed into a regular-sized human with a smaller hat!" If you are relating the story to someone after the event (which is what is happening in post #1), you would say "At the magic show last night, when the smoke cleared, the genie had transformed into a regular-sized human ...!" The transformation took place before both the smoke clearing and your seeing the genie.