Grammar topics include present simple and present continuous tenses, the present perfect, prepositions, relative clauses, modal verbs, adjectives, the first conditional, phrasal verbs and much ...
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.
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.