When you say something like "If you need help, my name is Jill," you aren't using if the way we normally think of using it. Your name is Jill no matter what. Syelle Graves explains what is going in this type of sentence.
Today’s topic is the funny case of a special kind of if-clause, which is also a conditional mood construction. It’s special because where we expect that one part of the sentence must be true in order for the other part to be true, it logically can’t be so. When taken literally or interpreted as the unintended non-sequitur, these constructions can be funny. For example, a comedian named Demetri Martin once joked about a shop clerk who led him to the changing room having a "conditional identity" because she said, “If you need anything, I’m Jill.” (6). Yet, we hear people say similar sentences a lot. To understand more about them, let’s first define the regular conditional mood and the if-clause, and then come back to this quirky type at the end.
The Conditional Mood Is Expressed with Modal Auxiliary Verbs
A language mood is like an attitude that is expressed with grammar or with words, and the conditional mood expresses probability, possibility, and also the fact that some things cause or lead to other things. To express it, we use modal auxiliary verbs like would, should, and could. (7) For example,
(1) Kindness should be rewarded.
That one expresses an opinion. Another example is
(2) We could take the day off today.
That one expresses possibility, or an option. Other modals, such as may and can are also used to express varying degrees of possibility in conditional mood sentences. (5) The modal might is used to express the potential or ability of the subject of the sentence, like “Noelle might join us,” which makes sense when you think of the relationship to the old-fashioned meaning of “might” to mean “power” (like the old idiom “with might and main”).
In contrast, regular, default sentences, meaning sentences that are not in any mood, and instead simply state facts or questions, are referred to as being in the “indicative mood.” (7) You can read more about conditionals here, and more about modals here.