It is + adjective + wh clause

Question

It is funny how you say that.
It is amazing what you did.
It is terrible why it happened.

Those sentences have same structure: It is + adjective + wh clause.

My question is, is it always possible to use this sentence structure with ANY adjective? I sometimes find this sentence hard to use with some adjectives like "happy".

Also, please tell me the name of this sentence. It would help me greatly. Thank you.

Answer 1

I'm trying to think of adjectives that wouldn't work here. Using the adjective "furry" or another adjective describing a physical trait struggles to work in your case.

The closest I can come to using furry in a sentence like yours is below, but it doesn't look like it works.

It is furry what you made your dog.

Answer 2

They all are correct.

Consider the following sentences -

1. How you say that is funny.
   
2. What you did is amazing.
   
3. What happened is terrible.

These sentences make sense and indeed correct.

Consider sentence #2

What you did is amazing.

The bold part - what you did - is either a fused relative construction or an open interrogative.

Consider sentence #3

What happened is terrible.

The bold part - what happened - is either a fused relative construction or an open interrogative.

Consider sentence #1

How you say that is funny.

The bold part - how you say that - is an open interrogative, not a fused relative clause.

A fused relative construction can never occur in extraposition construction. But an open interrogative can.

The following sentences are correct -

It's possible that out team might win.

Here that is a subordinator and it introduces a subordinate clause to complete the meaning.

It's I who did it.

In this sentence who did it is a relative construction and who a relativizer. The relative construction is adding some information about its antecedent - I.