Conditional verbs are used to create conditional sentences. Of course, there are other words which contribute to making a sentence conditional, but the verb tenses are key. The auxiliary verbs like can/could, will/would, and might are also key. Conditional verbs can be used in past, present or future tense.
If my cousin had been just a little taller, he could have been a basketball player.
If my cousin were just a little taller, he could have been a basketball player.
Were is a conditional verb because it’s used to form the subjunctive.
If I had enough money, I would travel around the world.
We’ll come help you move if we can borrow a truck.
Sometimes, there conditional tone will be created by the juxtaposition of verb tenses. In this sentence, the present tense makes the future tense conditional (but they need the word if to complete the tone).
If Alex finishes his essay, he’ll come over tomorrow.