In English, we use the verb "want" in two different ways. The first way is to say "I want an apple," simply stating desire for an object. The second is to say "I want to see a movie." This is a more complicated form, grammatically, and it involves using the verb "want" as a helping verb for "to see," the primary verb. This is what we will cover in this article, how to say "want" + [a verb].
In Japanese, the verb "want" is not actually a second verb, but rather a new conjugation of the primary verb. However, like many Japanese conjugations, it is simply based off another conjugation pattern. This is nice for foreign learners, and keeps things eaiser to learn.
To get the -tai form of a verb, first you must put the verb into the -masu form. We'll use the examples taberu (to eat), iku (to go), suru (to do), and au (to meet). Putting them in the -masu form, we get tabemasu, ikimasu, shimasu, and aimasu. At this point, remove the -masu. This leaves us with tabe, iki, shi, and ai. The final step is to add -tai to the end of the -masu stem. Our verbs come out as tabetai, ikitai, shitai, and aitai. Here is another way to see the conjugations form:
taberu --> -masu form --> tabemasu --> remove -masu --> tabe --> add -tai --> tabetai
This is one of the easier verb forms in Japanese, since it is based off the commonly-used -masu form. However, it is still very important to learn, and very useful. The same conjugation pattern is used for every verb, so from now on, every time you learn a new verb in the -masu form, you can form the -tai form as well!