Learn Hardcore Korean: nalssiga an johaseo yeonghwareul boji anha. - The weather isn’t good, so I’m not watching the movie.

-가 is the subject particle used when introducing new information or emphasizing the subject. -는 is the topic particle, often used for general statements or contrast. Here, the speaker highlights the weather as the reason for not watching a movie, so 가 is more natural.

What does 안 좋아서 mean and why is it formed this way?

안 좋다 means “to be not good.” Adding -아서/어서 to an adjective stem creates a connective ending meaning “because” or “and so.” The negative adjective stem 안 좋- plus -아서 becomes 안 좋아서, meaning “because it’s not good.”

Why is it 영화를 보지 않아 instead of 영화를 보지 않는다 or 영화를 보지 않아요?

This sentence uses the casual present form ~지 않다. In casual speech:

보지 않아 is the informal casual ending.
보지 않는다 is the written or neutral declarative present.
보지 않아요 is the polite form.
So 보지 않아 fits a relaxed, everyday style.

Why is the object 영화를 marked with -를?

영화 ends with the vowel ‘아’, so the object particle -를 attaches (whereas -을 attaches to consonant-ending nouns). 영화를 marks movie as the direct object of 보다 (“to watch”).

Is the verb tense present, past, or future?

It’s present tense. 보지 않아 literally means “do not watch.” If you wanted a clear past meaning, you’d say 보지 않았어 (casual) or 보지 않았어요 (polite).

Can I make this sentence more polite by adding -요?

Yes. Simply change 보지 않아 to 보지 않아요 (polite present):
날씨가 안 좋아서 영화를 보지 않아요.

Could this sentence mean “I didn’t watch a movie because the weather wasn’t good”?

In casual conversation, present-tense informal forms sometimes convey past events. Listeners infer timing from context. To be unambiguously past, use:
날씨가 안 좋아서 영화를 보지 않았어.
or add a time marker: 어제 날씨가 안 좋아서…