Quelle heure est-il ?

Because heure is a feminine singular noun in French, so the question word has to agree with it.

• quel = masculine singular
• quelle = feminine singular
• quels = masculine plural
• quelles = feminine plural

So with heure, you need quelle: Quelle heure est-il ?

Because quelle is used before a noun and means what or which in that structure.

Here, heure is the noun, so French says quelle heure.

Compare:

• Quelle heure... ? = What time... ?
• Que and quoi are not used directly before a noun like this in standard French.

So English what time becomes French quelle heure.

In Quelle heure est-il ?, il is an impersonal subject. It does not refer to a male person.

This is similar to English it in:

• What time is it?
• It is three o’clock.

In French, time expressions often use this impersonal il:

• Il est deux heures
• Il est midi
• Il est tard

So the il here is just part of the normal structure.

This is because French often forms questions by inversion, which means the verb and subject switch places.

Statement:

• Il est deux heures.

Question:

• Est-il deux heures ?
• Quelle heure est-il ?

In this sentence, est-il is the standard inverted form.

That said, in everyday spoken French, people very often say:

• Il est quelle heure ?

Both are understood, but Quelle heure est-il ? is the standard textbook form.

French uses the singular noun heure in this fixed expression.

Literally, the structure is closer to which hour is it?, even though the natural English meaning is what time is it?

So even if the answer may later include a plural:

• Il est trois heures

the question itself still uses singular:

• Quelle heure est-il ?

Yes, people do say it, and it is completely correct. It sounds standard and natural.

However, in casual spoken French, many speakers prefer:

• Il est quelle heure ?

So a good way to think about it is:

• Quelle heure est-il ? = standard, careful, very common in writing and teaching
• Il est quelle heure ? = very common in everyday speech

A common pronunciation is roughly:

kel ur eh-teel

More precisely in IPA:

/kɛ.lœʁ ɛ.til/

A few useful points:

• heure starts with a silent h
• the l of quelle links smoothly into heure
• in est-il, the t is pronounced, so it sounds like eh-teel

That t sound is important in the inverted question form.

Because quelle already acts as the determiner for the noun.

In English, compare:

• What time... not
• What the time...

French works similarly here:

• Quelle heure... not
• Quelle l’heure...

So no article is used after quelle.

You normally answer with Il est...

Examples:

• Il est une heure.
• Il est deux heures.
• Il est trois heures et demie.
• Il est midi.
• Il est minuit.

A small detail:

• use heure in the singular only with une heure
• use heures in the plural with most other numbers

So:

• Il est une heure
• Il est deux heures

Not really. A word-for-word translation would not sound natural.

French has its own fixed expression:

• Quelle heure est-il ?

So it is best to learn this as a whole pattern rather than trying to build it directly from English word by word.