Used as a verb. Use to + verb is a regular verb and means something that happened but doesn't happen any more. It uses -ed to show past tense. But since it always means something that happened in the past, it should always use past tense.

Whats the difference between use and uses?

As verbs the difference between use and uses

is that use is (archaic) to accustom; to habituate while uses is (use).

IS uses a plural or singular?

The noun use can be countable or uncountable. In more general, commonly used, contexts, the plural form will also be use. However, in more specific contexts, the plural form can also be uses e.g. in reference to various types of uses or a collection of uses.