Vedän oven kiinni, koska ulkona on kylmä.

Vedän is the 1st person singular present tense of the verb vetää = to pull.

So:

• minä vedän = I pull
• sinä vedät = you pull
• hän vetää = he/she pulls

In this sentence, vedän is used in a very natural Finnish way: vedän oven kiinni means literally I pull the door shut.

Because ovi (door) is the object of the verb, and here it appears in the genitive/accusative-like object form oven.

• ovi = door
• oven = the door / door as a completed object here

In vedän oven kiinni, the action affects the whole door and reaches a clear result: the door ends up shut. Finnish often uses this total object form when the action is completed.

Compare:

• Vedän ovea. = I am pulling the door / I pull on the door
  → focus on the ongoing action
• Vedän oven kiinni. = I pull the door shut
  → focus on the completed result

Kiinni means something like closed, shut, fast, or attached, depending on context.

In this sentence, oven kiinni means the door shut/closed.

So:

• vetää ovi kiinni type structure = pull a door shut
• laittaa ovi kiinni = put/leave a door closed
• pitää ovi kiinni = keep a door closed

Here kiinni is not an adjective agreeing with ovi. It behaves more like a fixed adverbial word in expressions about closing something.

It often can. A very common alternative is:

• Suljen oven, koska ulkona on kylmä. = I close the door because it’s cold outside.

But vedän oven kiinni is also natural. It gives a slightly more physical sense: I pull the door shut.

So the difference is roughly:

• sulkea ovi = to close the door
• vetää ovi kiinni = to pull the door shut

Both are correct; this sentence just uses a more concrete everyday expression.

Koska means because here.

It introduces the reason:

• Vedän oven kiinni = I pull the door shut
• koska ulkona on kylmä = because it is cold outside

So the whole sentence is:

• Vedän oven kiinni, koska ulkona on kylmä.

Be careful: koska can also mean when in some contexts, but in this sentence it clearly means because.

Because in Finnish, a subordinate clause is normally separated by a comma.

Here:

• main clause: Vedän oven kiinni
• subordinate clause: koska ulkona on kylmä

So the comma is standard Finnish punctuation.

Ulkona means outside or outdoors.

It comes from ulkona, which is a form related to ulkona/ulkona being outside. More specifically, it is the essive/location-type form of ulkona from ulko- concepts, and it means in the state/place of being outside.

For a learner, the most useful thing is simply:

• ulkona = outside
• ulos = out / to the outside

Compare:

• Lapsi on ulkona. = The child is outside.
• Lapsi menee ulos. = The child goes outside.

So in your sentence, ulkona on kylmä means it is cold outside.

In Finnish weather expressions, the usual pattern is:

• on kylmä = it is cold
• on kuuma = it is hot
• on pimeää = it is dark

With kylmä, the nominative adjective is very common in expressions like this:

• Ulkona on kylmä. = It’s cold outside.

This is a standard and natural way to say it.

Finnish weather expressions do not always match English structure exactly. English uses a dummy subject it, but Finnish simply says:

• on kylmä = is cold

There is no separate word for it here.

There is no word for it. Finnish often leaves out the subject in weather and general-condition expressions.

English says:

• It is cold outside.

Finnish says:

• Ulkona on kylmä.
• literally: Outside is cold.

This is completely normal. Finnish does not need a dummy subject like English it in this kind of sentence.

Yes, Finnish word order is quite flexible, although some orders sound more neutral than others.

The given sentence:

• Vedän oven kiinni, koska ulkona on kylmä.

is a neutral, natural order.

You could also say:

• Koska ulkona on kylmä, vedän oven kiinni.

That puts more emphasis on the reason first:

• Because it’s cold outside, I pull the door shut.

Both are correct.

Usually it suggests an actual pulling motion, or at least the kind of closing action you would naturally describe that way.

For example, if a door opens toward you, you might pull it shut:

• vedän oven kiinni

If you want a more general verb with no emphasis on motion, use:

• suljen oven = I close the door

So vedän oven kiinni is not just a word-for-word translation of English I close the door. It has its own natural Finnish feel.

Yes. Finnish present tense is used both for:

• general present actions
• actions happening right now
• near-future actions in context

So Vedän oven kiinni can mean:

• I pull the door shut
• I’m pulling the door shut
• sometimes even I’ll pull the door shut depending on context

In this sentence, it most naturally means something like I’m pulling / I pull the door shut because it’s cold outside.

Yes, but the meaning changes a bit.

• Vedän oven kiinni = I pull the door shut
• Painan oven kiinni = I push/press the door shut
• Laitan oven kiinni = I close the door / put the door closed
  This is very common in everyday speech.
• Suljen oven = I close the door

So the choice depends on the physical action and the tone you want. The original sentence is perfectly natural if the idea is specifically pulling the door shut.