If such a huge meteor had really crashed into the Earth, why isn't there even a little piece of evidence such as crater anywhere on Earth?
2 .If he were really a famous singer, why can't he sing very well?
As you see, subjunctive mood (had crashed and were) is used in these bold parts to express the hypothetical situation that is supposed to be not real to the writers who wrote these two sentences, but is it grammatically correct to combine subjunctive mood with present tense as in "why isn't" and "why can't"?
As far as I know, present tense cannot be used with subjunctive mood, so I'm asking this question.
fire1 If such a huge meteor had really crashed into the Earth, why isn't there even a little piece of evidence such as crater anywhere on Earth? The past perfect is a dependent tense. It depends on establishing some point in the past as an anchor.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
fire1If such a huge meteor had really crashed into the Earth, why isn't there even a little piece of evidence such as crater anywhere on Earth?
The past perfect is a dependent tense. It depends on establishing some point in the past as an anchor. The contents of the past perfect clause is then anterior to (before) the contents of the anchor
fire1If he were really a famous singer, why can't he sing very well?
Here again "were" is out of place.
If he is really a famous singer, why can't he sing very well?
I don't see anything here that requires a subjunctive.
I suspect that part of the problem is that both of your examples end in questions that presuppose a present state