This is sometimes called the “if clause” and describes a definite result that will follow if some conditions are met. The structure of such a sentence often follows this pattern: if… then.
“If” in the sentence structure serves as the condition, while “then” is the result. Often, “then” doesn’t appear as much as “if” in the sentence, with a comma used to introduce the result of the conditional sentence.
These are some examples of conditional sentences:

