Question

correct tense all that (glitter) (be) not gold​

Answer 1

Answer:

The pronoun all can be singular or plural, depending on what it refers to. We don't know exactly what all refers to here, but we know it refers to something singular, because its modifier—that glitters—is singular. So we have a singular subject. Thus the verb should be singular: All that glitters is not gold.

Answer 2

Answer:

All that glitters is not gold.