watasi ha tosyokan de sinbun wo yomimasu.

The particle は marks the topic of the sentence—what the sentence is “about.” Here, 私 (I) is introduced as the topic (“As for me…”). If you used が (私が), you’d be marking it as the subject in a neutral or emphatic context (“It is I who read the newspaper”), often to contrast or answer a question like “Who reads the newspaper?”

で indicates where an action takes place (“at/in”), while に marks a destination, point in time, or state of existence.

• 図書館で新聞を読みます: “I read a newspaper at the library.” (action location)
• 図書館に行きます: “I go to the library.” (destination)
• 家にいます: “I am at home.” (state of existence)

The particle を marks the direct object—the thing being acted upon. In 新聞を読みます, 新聞 is what you read. Without を, the verb wouldn’t know what object to act on.

Japanese follows a Subject–Object–Verb (SOV) order. After introducing the topic (私は), any further elements like location (図書館で) and object (新聞を) come before the verb. The sentence ends with the verb 読みます (“read”).

• 読む is the dictionary/plain form, used in casual speech or in writing.
• 読みます is the polite present/future form, used in formal or polite conversation. They mean the same action (“to read”).

Yes. In Japanese, when the subject/topic is clear from context, pronouns are often dropped. 図書館で新聞を読みます still means “I read a newspaper at the library.”