Breakdown of gakusei ha nihongo wo hanasimasu.

Questions & Answers about gakusei ha nihongo wo hanasimasu.
Japanese typically follows S-O-V (Subject-Object-Verb) order:
• 学生は = Topic (“student”)
• 日本語を = Object (“Japanese language”)
• 話します = Verb (“speaks”)
In English we say “The student speaks Japanese” (S-V-O), but Japanese places the verb at the end.
話します is the polite present affirmative form of the verb 話す (“to speak”).
• 話す = plain/dictionary form
• 話します = polite/formal speech often used in everyday conversation, especially with people you don’t know well or in formal settings.
Yes, you could say 学生が日本語を話します, but that shifts the nuance:
• 学生は… = “As for the student, he/she speaks Japanese.” (topic emphasis)
• 学生が… = “It’s the student who speaks Japanese.” (subject emphasis or contrast, e.g. not the teacher)
You replace 学生は with 私 (or 私は) and keep everything else the same:
• 私は日本語を話します。
This literally means “As for me, I speak Japanese.”