Tips:
It might be a noun clause...
if the clause functions as the subject or object of the sentence
if the word "if" in the sentence can be replaced with the word "whether".
It might be an adverb clause...
if the clause is a conditional sentence
if the clause expresses an if/then situation
Noun Clauses or Adverb Clauses with "if" 1

Directions: Decide whether the clauses with “if” in the following sentences are noun clauses or adverb clauses.
A Rain Check
It’ll be terrible if it rains tomorrow (1). If it rains (2), I will have to postpone the party. I don’t know if it’s going to rain (3). If I cancel the party (4), I’ll have to call people. What should I do if they have already left (5). If they come to the house and no one is here (6), they’ll be upset. I’m not sure if I should cancel the party anyway (7). If I cancel the party and it doesn’t rain (8), I’ll be upset. Come to think of it, I will have the party even if it rains (9). I don’t really care if it rains (10).

