oneul sikdang banchani neomu jjaseo mureul manhi masyeosseo.

짜서 comes from 짜다, which means to be salty.

• 짜다 → stem 짜-
• add -아서/어서
• 짜 + 아서 contracts to 짜서

Here, -아서/어서 shows a reason or result, so 짜서 means because it was salty or it was so salty that...

Also, in Korean, words that translate as adjectives in English often conjugate like verbs, so 짜다 changes form just like a verb would.

In Korean, the final verb often carries the tense for the whole sentence.

So in:

• 반찬이 너무 짜서 물을 많이 마셨어

the past tense on 마셨어 already tells you the whole situation happened in the past.

Using 짜서 is normal because the saltiness is the state that caused the drinking. Korean usually does not need to mark that earlier part separately as past in this kind of sentence.

It can mean either, depending on context.

• traditionally, 너무 often means too much / excessively
• in everyday Korean, it is also very often used as very / really

In this sentence, because the speaker drank a lot of water, 너무 짜서 sounds like so salty or too salty.

Time expressions often appear with no particle in Korean.

So 오늘 by itself simply means today and works naturally at the beginning of the sentence.

You could say 오늘은 if you wanted contrast or emphasis, like:

• 오늘은 식당 반찬이 너무 짜서...
• As for today, the restaurant side dishes were so salty...

But the version without a particle is very common.

Korean often puts one noun directly before another noun to modify it.

So:

• 식당 반찬 = restaurant side dishes / the restaurant's side dishes

Using 의 is possible, but it is often omitted when the relationship is obvious.

• 식당 반찬 sounds natural and conversational
• 식당의 반찬 sounds a little more explicit, and sometimes a bit more formal

Because 식당 here is modifying 반찬, not showing where the action happened.

• 식당 반찬 = the restaurant side dishes
• 식당에서 = at the restaurant

So the sentence is focusing on which side dishes they were: the ones from the restaurant.

If you said:

• 오늘 식당에서 반찬이 너무 짜서 물을 많이 마셨어

that would mean something like Today, at the restaurant, the side dishes were so salty that I drank a lot of water. That is also possible, but the structure and focus are slightly different.

이/가 marks the grammatical subject, while 은/는 marks the topic and often adds contrast.

So:

• 반찬이 너무 짜서 = neutral statement about the side dishes being salty
• 반찬은 너무 짜서 = as for the side dishes, they were too salty, possibly with a contrastive feeling

The version with 이 is a straightforward way to present the cause.

Korean nouns usually do not change form for singular vs. plural.

So 반찬 can mean:

• a side dish
• side dishes
• side dish food collectively

In this sentence, English will usually translate it as side dishes, because that sounds most natural in context.

Korean very often leaves out subjects when they are clear from context.

In this sentence, 마셨어 tells us someone drank water, and in normal conversation it is very natural to understand that as I drank.

If you wanted to include it, you could say:

• 나는 오늘 식당 반찬이 너무 짜서 물을 많이 마셨어.

But Korean usually prefers to omit it when it is obvious.

Korean word order is flexible, but some orders sound more natural in neutral speech.

Here, 많이 modifies 마셨어, so putting it right before the verb is very natural:

• 물을 많이 마셨어 = drank a lot of water

You can also say:

• 많이 물을 마셨어

but that tends to put a bit more emphasis on a lot.

So the original order is the most neutral and common one.

을/를 marks the direct object of the verb.

So:

• 물 = water
• 물을 = water as the thing being drunk

In English, we do not have a separate object marker like this, but in Korean it helps show what receives the action.

Also, 물을 does not automatically mean the water. Depending on context, it can mean:

• water
• some water
• the water

마셨어 is informal casual speech.

It is the kind of form you would use with:

• close friends
• younger people
• someone you speak casually with

If you wanted to make it polite, you would say:

• 마셨어요

If you wanted a plain written/dictionary-style statement, you could say:

• 마셨다