Lính ở gần cửa.

Vietnamese does not use là for physical location the way English uses is/are.

In Lính ở gần cửa, the word ở already expresses location, so the sentence is complete as it is.

• ở = to be at, stay at, be located at
• là = to be in the sense of identification/equation, as in Anh ấy là bác sĩ (He is a doctor)

So:

• Lính ở gần cửa = correct
• Lính là gần cửa = not correct

Here, ở means to be at / to be located at.

It can also mean to live in other contexts:

• Tôi ở Hà Nội can mean I live in Hanoi
• Anh ấy ở ngoài sân means He is outside in the yard

So in this sentence, ở is marking location, not residence.

It can mean either soldier or soldiers, depending on context.

Vietnamese nouns usually do not change form for singular vs. plural. So lính by itself is number-neutral.

If you want to make the number clear, Vietnamese can add other words:

• một người lính = one soldier
• những người lính = soldiers
• mấy người lính = several soldiers

So bare lính leaves it open unless the context tells you.

Vietnamese normally does not use articles like English a/an/the.

Whether lính means a soldier, the soldier, or soldiers depends on context.

Vietnamese can make things more specific in other ways, for example:

• người lính đó = that soldier
• một người lính = a soldier
• những người lính ấy = those soldiers

But in a simple sentence like Lính ở gần cửa, Vietnamese often leaves that unstated.

Gần means near or close to.

In Vietnamese, gần goes directly before the noun:

• gần cửa = near the door
• gần nhà = near the house
• gần trường = near the school

English uses near the door or close to the door. Vietnamese does not need a separate word like to here.

The sentence follows a very straightforward pattern:

subject + ở + location

So:

• Lính = the person/thing being talked about
• ở = is located at
• gần cửa = near the door

That gives:

Lính ở gần cửa.

This is a very common Vietnamese pattern for saying where someone or something is.

Usually, cửa means door.

Depending on context, it can also refer more generally to an entrance, gate, or opening. But in a basic sentence like this, door is the most natural understanding.

Related expressions include:

• cửa ra vào = entrance door
• cửa sổ = window
• ngoài cửa = outside the door / at the doorway

Normally, if you mean The soldier is near the door, you should keep ở.

• Lính ở gần cửa = natural, complete sentence
• Lính gần cửa = less natural as a full statement, and may sound shortened or elliptical

Vietnamese usually uses ở when stating location directly.

Both are possible, but they are a little different in feel.

• lính = soldier(s), often shorter and more direct
• người lính = soldier, more explicitly referring to a person

In many contexts, lính sounds perfectly natural.
Người lính ở gần cửa is also correct, but slightly fuller.

So the short form in your sentence is normal.

Not exactly.

• gần cửa = near the door
• ở cửa = at the door / by the door

gần cửa suggests being close to the door, but not necessarily right at it.
ở cửa places the person more directly at the door area.

So they are similar, but not identical.

You can add đang:

• Lính đang ở gần cửa.

đang shows an action or state that is in progress or currently true, so it often gives the sense of is/are currently.

Without đang, the sentence can still mean present time; it is just more neutral.

A rough guide is:

• lính — rising tone
• ở — dipping/rising tone in Northern Vietnamese
• gần — falling tone
• cửa — dipping/rising tone in Northern Vietnamese

The tones matter a lot, especially in short sentences like this.

A very rough English-style approximation would be something like:

linh uh gunn koo-uh

But that is only approximate. The real Vietnamese vowel sounds and tones are important, especially in ở and cửa.

It can do either, depending on context.

A bare Vietnamese sentence like Lính ở gần cửa does not mark tense the way English usually does. So it could mean:

• a current situation
• a general description
• part of a narrative

If you want to make time clearer, Vietnamese can add time or aspect words:

• Lính đang ở gần cửa = is/are near the door now
• Lính đã ở gần cửa = was/were or had been near the door
• Lính sẽ ở gần cửa = will be near the door

So the original sentence is grammatically neutral about time unless context fills it in.