Hải sản này hơi mặn.

• hải sản = seafood
• này = this
• hơi = a little, slightly
• mặn = salty

A very literal word-for-word order is:

• seafood this slightly salty

That is normal Vietnamese word order.

Vietnamese often does not use a separate verb like to be before adjectives.

So:

• Hải sản này hơi mặn = This seafood is a little salty.

You do not normally say:

• Hải sản này là hơi mặn

In Vietnamese, adjectives like mặn can act like the predicate by themselves. This is a very common pattern:

• Cà phê này đắng = This coffee is bitter.
• Canh này nóng = This soup is hot.

In Vietnamese, demonstratives like this and that usually come after the noun.

So:

• hải sản này = this seafood
• món này = this dish
• nhà đó = that house

This is one of the big word-order differences from English.

A useful pattern is:

• noun + này = this noun
• noun + đó / kia = that noun

Hơi means slightly, a little, or somewhat.

It softens the statement. So hơi mặn sounds less strong than just mặn.

Compare:

• mặn = salty
• hơi mặn = a little salty
• khá mặn = quite salty
• rất mặn = very salty
• quá mặn = too salty / excessively salty

In conversation, hơi is useful because it can make criticism sound gentler.

Because the basic sentence pattern here is:

• noun phrase + adjective

So:

• Hải sản này = this seafood
• hơi mặn = slightly salty

Together:

• Hải sản này hơi mặn

This is normal Vietnamese structure for describing something.

English usually says:

• This seafood is slightly salty

Vietnamese often just places the describing word after the noun phrase, without is.

It is usually taught as an adjective, but in sentences like this it behaves a bit like a stative verb.

That is why it can stand directly in the predicate:

• Nước này lạnh = This water is cold.
• Thịt này dai = This meat is chewy.
• Hải sản này hơi mặn = This seafood is a little salty.

So if you are an English speaker, it helps to think:

• the word is an adjective in meaning,
• but it can function like the main verb of the sentence.

Not necessarily.

Hải sản can be used on its own when you mean seafood in a general sense, or when the context already makes it clear what food you are talking about.

So Hải sản này hơi mặn is natural.

But if you want to refer to a specific dish more explicitly, you could say:

• Món hải sản này hơi mặn = This seafood dish is a little salty.

So:

• Hải sản này = this seafood
• món hải sản này = this seafood dish

Both can be correct depending on context.

Vietnamese nouns usually do not change form for singular vs. plural the way English nouns do.

So hải sản can refer to:

• seafood in general,
• a seafood dish,
• seafood items, depending on context.

The sentence itself does not force a singular/plural distinction. You understand it from the situation.

The tones are:

• Hải = hỏi tone
• sản = hỏi tone
• này = huyền tone
• hơi = ngang tone
• mặn = nặng tone

A few helpful notes:

• hỏi often sounds like a dipping or questioning tone
• huyền is low and falling
• ngang is level
• nặng is low, short, and glottalized/stopped

Also remember that ơ in hơi is a vowel quality, not a tone mark.

If you are practicing, say it slowly first:

• Hải sản này hơi mặn

Then speed up naturally.

You can change the degree word:

• Hải sản này mặn. = This seafood is salty.
• Hải sản này hơi mặn. = This seafood is a little salty.
• Hải sản này khá mặn. = This seafood is quite salty.
• Hải sản này rất mặn. = This seafood is very salty.
• Hải sản này quá mặn. = This seafood is too salty.

To sound more polite in conversation, you could add a polite particle at the end, depending on the situation:

• Hải sản này hơi mặn ạ.

That can sound softer and more respectful, especially when speaking to staff, elders, or someone you do not know well.