There is a misconception that all verbs in a paragraph should be in the same tense. The choice of the appropriate verb tense depends on context and meaning.

choose an appropriate verb and use it well. In particular, use it in the right tense, choose carefully between active and passive voice, and avoid dangling verb forms. Verbs are for describing ...

Keep in mind that each sentence you write will need to have agreement between its subject and verb. The following explains how to conjugate a regular present tense verb: They eat pizza. Unfortunately, ...

One’s tense will vary depending on what one is trying to convey within their paper or section of their paper. For example, the tense may change between the methods section and the discussion section.