All Japanese verbs are divided into three groups.
辞書形（基本形） Dictionary (Basic) Form
The dictionary form (basic form) of all Japanese verbs end with “u”.
This is the form listed in the dictionary, and is the informal, present affirmative form of the verb. This form is used among close friends and family in formal situations.
ます形 masu form
“masu” is used when a sentence express a habitual thing or a truth. It is also used when a sentence expresses a thing that will occur in the future.
Group1: Take off the final “～u”, and add “～imasu”.
Group2: Take off the final “～ru”, and add “～masu”.
Group3: “suru” becomes “shimasu”, “kuru” becomes “kimasu”.