What do you mean there's no future tense?
Some people have trouble accepting that English lacks a future tense. If you are in that group, there are several points to keep in mind. First, remember that tense is not the same as time. To say that English lacks a future tense does not mean that it has no way of referring to the future. It has many ways to do that. In English, the future is a time-reference, but not a tense. Second, English may lack a future tense, but other languages do have one, particularly languages you are likely to have studied in school, such as Spanish, French, or Latin. Indeed, the tense system of Latin is partly at fault for the way that tense is taught today. When the early grammarians sat down to write the first grammars of English, they took Latin as the model, and simply filled in the categories that worked for Latin with their nearest English equivalents. It should not be surprising that different languages should vary in how many tenses they have. After all, one of the reason that languages are different is because they follow different sets of rules. There is nothing logically necessary about dividing time up into past, present, and future, and even given a three-fold distinction, there is no logical requirement that each distinction must be expressed through tense.