Learn Hardcore Korean: doseogwane gaseo chaegeul ilgeoyo. - I go to the library and read a book.

에 marks the destination or direction of movement (“to the library”). In contrast, 에서 marks the location where an action occurs (“at the library”). Since 가다 (to go) expresses movement toward somewhere, you use 에.

What function does 가서 serve, and how does the -아서/-어서 form work?

가서 is made from 가다 (to go) + -아서 (after doing). This connective ending links two verbs to show sequence or cause: “go and then…”. In 도서관에 가서 책을 읽어요, it means “I go to the library and then read a book.”

How is 가서 different from using 가고 to connect verbs?

-고 simply lists actions (“A and B”), without implying order or cause. -아서/-어서 implies that the first action leads into the second.
• 도서관에 가고 책을 읽어요 = “I go to the library and I read a book” (neutral list).
• 도서관에 가서 책을 읽어요 = “I go to the library and then I read a book” (sequence/continuation).

Why is 읽어요 placed at the end of the sentence?

Korean uses Subject-Object-Verb (SOV) word order. All verbs (and adjectives) come at the end of their clause, so 읽어요 naturally finishes the sentence.

Why is there no subject like I or she at the beginning?

Korean often omits the subject when it’s clear from context. If you want to be explicit, you could say 저는 도서관에 가서 책을 읽어요 (“I go to the library and read a book”), but dropping 저는 is perfectly normal.

Why do we use the object marker 을 after 책?

Direct objects take -을 after a consonant and -를 after a vowel. Since 책 ends in the consonant ㄱ, it takes -을: 책을 읽어요.

What level of politeness is 읽어요, and when would I use it?

읽어요 is the polite informal (해요체) present tense. It’s appropriate for everyday conversations with strangers, acquaintances, or people older than you when you want to be polite but not overly formal.

Why isn’t a location particle used again before 책을 읽어요 to show where the reading happens?

Once you’ve established 도서관에 가서, the location carries over to the next action. You understand that reading happens at the library. If you really need to emphasize where you read, you could say 도서관에서 책을 읽어요 (“I read a book at the library”).

How can I express “I go to the library to read a book” (showing purpose)?

Use the purpose‐forming ending -으러 on the verb stem:
도서관에 책을 읽으러 가요.
This literally means “I go to the library in order to read a book.”

Can I drop the object marker 을 and say 도서관에 가서 책 읽어요?

In casual spoken Korean, native speakers often drop particles when the meaning is clear. However, as a learner (and especially in writing), it’s better to include 을: 책을 읽어요 to keep your grammar clear and unambiguous.