What kind of clause cannot stand on its own to form a sentence?

Answer 1

subordinate or dependent clauses cannot stand alone

Answer 2

The above answer is correct!

Clauses all contain a subject and a verb. Independent clauses can stand alone - just like a full sentence! Dependent (AKA subordinate) clauses have a conjunction which makes them depend on the rest of the sentence - they cannot stand alone.

Ex:

I went to the store. (Independent clause)

When I went to the store, … (Dependent clause)

The subject and verb are the same, but the dependent clause leaves you wanting more. It depends on the information given in the rest of the sentence. For that reason, it cannot stand alone.