future tense clauses

[danda]

Hi, I would like to ask about the grammar concerning the future tense. It is so called future tense clause, one example : I´ll be ready as soon as I´ve had a shower. I just do not understand the use of the present perfect tense:shock:
Why the present perfect instead of the present simple???
thank you!

 

[Richard1]

Hi,

Because the process of having a shower is not yet complete, and you can't be ready until the shower has finished.

Regards

 

[Raymott]

Hi, I would like to ask about the grammar concerning the future tense. It is so called future tense clause, one example : I´ll be ready as soon as I´ve had a shower. I just do not understand the use of the present perfect tense:shock:
Why the present perfect instead of the present simple???
thank you!

There are many examples where either tense works (simple or perfect). This, to me, is one.
"I'll be ready as soon as I have a shower" gives the same meaning.
You'll note that this is similar to the simple past/past perfect:
"He was ready as soon as he had a shower" = "He was ready as soon as he had had a shower"

The reason you can choose which tense to use is that "as soon as" is a time marker. If A happens as soon as B happens, then B occurs before A whichever tenses you want to frame it in.
You'll find that if you use time markers (usually adverbs like 'before', 'after', 'since'), that it's quite unnecessary to use tense changes to make the sentence understandable.