Most novels are written in the past tense. Readers are more familiar with this tense because they are used to being told a story that has already taken place. For most verbs you add an ‘ed’ at ...

For example, the tense may change between the methods section and the discussion section. The abstract is usually in the past tense due to it showing what has already been studied. Example: “This ...

There are variations in the way verbs form the past tense. They can be looked at in the following way: ...

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.