How many clauses are there in If you could come on Sunday that would be great?

There is one clause in the sentence "If you could come on Sunday, that would be great."

Here's why:

* Independent Clause: "That would be great" is the main clause and can stand alone as a complete thought.

* Dependent Clause: "If you could come on Sunday" is a dependent clause because it relies on the main clause for its meaning. It introduces a condition.

The dependent clause functions as an adverbial clause modifying the verb "would be" in the independent clause.