Breakdown of gakusei wa eiga o mimasu.

Questions & Answers about gakusei wa eiga o mimasu.
学生 is pronounced がくせい (gakusei), meaning “student.”
映画 is えいが (eiga), meaning “movie.”
見ます is みます (mimasu), the polite present tense of “to see/watch.”
見ます is the polite non-past form, covering both present and future (e.g. “watches” or “will watch”).
To make it past tense, say 見ました (mimashita).
To make it negative, say 見ません (mimasen).
は marks the topic or contrasts information, so 学生は… sets “student” as the theme.
が marks the grammatical subject or highlights new/important information. Using 学生が映画を見ます might emphasize “it is the student (not someone else) who watches the movie.”
見ます is the masu-form (polite) you’d use in formal or respectful contexts.
見る is the plain or dictionary form, used in casual speech, writing, or when listing verbs in a dictionary.