Some writers like to use the present tense to tell a story in order to give the impression that it is happening right now. In fiction writing the present tense can create a dramatic effect and ...

The abstract is usually in the past tense due to it showing what has already been studied. Example: “This study was conducted at the Iyarina Field School, and within the indigenous Waorani community ...

If’ usually introduces conditional clauses. The same applies to other conditionals such as unless, should and in case which, however, perform other functions in different contexts.