Áo sơ mi này đáng giữ.

Áo sơ mi means a shirt, especially a button-up or collared shirt in the usual Vietnamese sense.

A quick breakdown:

• áo = shirt / top / garment for the upper body
• sơ mi = specifically the shirt type

So áo sơ mi is more specific than just áo.

Examples:

• áo = shirt / top / clothing item
• áo thun = T-shirt
• áo sơ mi = dress shirt / button-up shirt

In Vietnamese, demonstratives like này usually come after the noun, not before it.

So:

• áo sơ mi này = this shirt
• literally: shirt this

This is normal Vietnamese word order.

Compare:

• cuốn sách này = this book
• ngôi nhà này = this house
• người này = this person

So Áo sơ mi này is the natural way to say this shirt.

Yes—from an English point of view, it may feel like something is missing, but in Vietnamese this is normal.

Áo sơ mi này đáng giữ literally looks like:

• This shirt worth keeping

Vietnamese often does not use a word equivalent to is in sentences where the predicate is adjectival or descriptive.

So:

• Áo sơ mi này đẹp. = This shirt is beautiful.
• Cái này tốt. = This is good.
• Áo sơ mi này đáng giữ. = This shirt is worth keeping.

There is no need to add a separate verb meaning is here.

Đáng means something like worth, deserving of, or worthy of.

In đáng giữ, it means:

• worth keeping
• deserving to be kept

A very common pattern is:

• đáng + verb

Examples:

• đáng xem = worth watching
• đáng đọc = worth reading
• đáng nhớ = worth remembering
• đáng giữ = worth keeping

So in your sentence, đáng giữ works as the idea is worth keeping.

Vietnamese often uses a simpler verb form where English might prefer a passive idea.

So đáng giữ literally uses the active verb giữ = keep, but the whole phrase is understood as:

• worth keeping
• deserves to be kept

You do not need a separate passive marker here.

English:

• This shirt is worth keeping.

Vietnamese:

• Áo sơ mi này đáng giữ.

That is already complete and natural.

Giữ basically means to keep, to retain, to hold on to, or sometimes to preserve depending on context.

In this sentence, the meaning is:

• not throw it away
• not give it away
• keep it for future use

So đáng giữ suggests the shirt is good enough, useful enough, or valuable enough that you should keep it.

Yes, slightly.

• giữ = keep
• giữ lại = keep back / keep and not let go / keep for later

So:

• Áo sơ mi này đáng giữ.
• Áo sơ mi này đáng giữ lại.

Both are understandable and natural, but giữ lại can sound a bit more explicit about keeping it instead of discarding or giving it away.

In many contexts, the shorter đáng giữ is perfectly fine.

It can be there, but it does not have to be.

You may hear both:

• Áo sơ mi này đáng giữ.
• Cái áo sơ mi này đáng giữ.

Both are grammatical.

About cái:

• It is a common classifier for many everyday objects.
• In natural speech, classifiers are often used, but they can also be omitted in some contexts, especially when the noun phrase is already clear and natural without them.

With clothing, Vietnamese often says:

• cái áo này
• chiếc áo này

But simply áo sơ mi này is also very normal.

Yes, it is natural and correct.

It sounds like a concise judgment: the speaker is saying the shirt is worth keeping.

Depending on tone and situation, a speaker might also say:

• Cái áo sơ mi này đáng giữ.
• Áo sơ mi này nên giữ lại. = This shirt should be kept.
• Nên giữ cái áo sơ mi này. = We/you should keep this shirt.

Your original sentence is a nice, compact way to express the idea.

They are similar, but not identical.

• đáng giữ = worth keeping
• nên giữ = should keep

Difference:

• đáng giữ focuses on the shirt’s value or merit
• nên giữ focuses more on advice or recommendation

So:

• Áo sơ mi này đáng giữ. = This shirt has enough value/quality to justify keeping it.

• Áo sơ mi này nên giữ. = This shirt should be kept.

In many contexts they are close, but đáng has more of the sense of being worthy.

Yes. This is a very useful pattern in Vietnamese.

Common examples:

• đáng xem = worth watching
• đáng nghe = worth listening to
• đáng đọc = worth reading
• đáng mua = worth buying
• đáng nhớ = worth remembering
• đáng tin = trustworthy / worth believing

So learning đáng + verb is very helpful.

Your sentence follows that same pattern:

• đáng giữ = worth keeping

A careful pronunciation would be roughly:

• Áo sơ mi này đáng giữ.

A broad English-friendly approximation:

• ow suh mee nye dangg zyu

But that is only approximate. The tones matter a lot:

• áo — rising tone
• sơ — level tone
• mi — level tone
• này — falling tone
• đáng — rising/broken tone
• giữ — rising/broken tone

A few notes:

• đ is like a regular English d
• giữ in northern pronunciation often starts with a z-like sound
• tones are essential for being understood

Yes. Đáng giữ can be broad.

Depending on context, it could mean the shirt is worth keeping because it is:

• high quality
• expensive
• still useful
• rare
• sentimental

So the sentence itself does not force only one reason. It simply says the shirt has enough value—of some kind—to justify keeping it.

Context tells you why.