Turvatarkastuksessa otan tietokoneen ja vesipullon pois käsimatkatavarasta.

Turvatarkastuksessa means at security screening / during the security check.

It comes from the noun turvatarkastus:

• turva = safety / security
• tarkastus = inspection / check

Together, turvatarkastus means security check.

The ending -ssa is the inessive case, which often means in or at. In this sentence, it gives the idea at the security check or during security screening.

So:

• turvatarkastus = security check
• turvatarkastuksessa = at/in the security check

In Finnish, the verb ending usually already tells you who the subject is, so the pronoun is often left out.

• otan = I take
• the ending -n shows first person singular

So minä is not necessary unless you want extra emphasis or contrast.

Compare:

• Otan tietokoneen. = I take out the computer.
• Minä otan tietokoneen. = I take out the computer.
  This sounds more emphatic, like contrasting with someone else.

They are the objects of the verb otan.

In Finnish, a total object often appears in a form that looks like the genitive singular, ending in -n. Here the sentence refers to taking out specific whole items, not just some amount of something.

So:

• tietokone = computer

• tietokoneen = the computer / a complete computer as object

• vesipullo = water bottle
• vesipullon = the water bottle / a complete water bottle as object

This is very common after verbs when the action is seen as complete or directed at the whole object.

Both parts have their own job:

• pois = away / off / out
• käsimatkatavarasta = from the hand luggage

Together they mean out of the hand luggage.

Finnish often uses pois with a case showing where something is removed from.

Examples:

• ottaa pois pöydältä = take away from the table
• ottaa pois laukusta = take out of the bag

So in your sentence:

• otan ... pois käsimatkatavarasta = I take ... out of my hand luggage

Using only käsimatkatavarasta might sound incomplete here, and using only pois would not tell you from where.

It is a compound word plus a case ending.

Base word:

• käsimatkatavara = hand luggage / carry-on baggage

This compound contains:

• käsi = hand
• matka = trip / travel
• tavara = goods / stuff / luggage

Then it gets the ending -sta, which is the elative case, meaning out of / from inside.

So:

• käsimatkatavara = hand luggage
• käsimatkatavarasta = out of/from the hand luggage

The singular is natural because the sentence is talking about one computer and one water bottle.

Finnish often uses singular nouns in exactly this kind of situation:

• tietokoneen = the/a computer
• vesipullon = the/a water bottle

If you meant several of each, you would use plural forms.

Also, Finnish has no articles like a or the, so the singular form can cover both depending on context.

Finnish has no articles like a/an or the.

So:

• tietokoneen can mean a computer or the computer
• vesipullon can mean a water bottle or the water bottle

The exact meaning depends on context. In a sentence about airport security, English would usually say something like the laptop and the water bottle or my laptop and water bottle, but Finnish does not need separate words for that.

The Finnish present tense can cover several meanings that English often separates.

Here otan can mean:

• I take out
• I'm taking out
• I will take out
• I take out as a usual procedure

In a sentence like this, it often sounds like a general statement about what one does at security screening:

• At security, I take my computer and water bottle out of my hand luggage.

So it may describe:

1. a habitual action,
2. an instruction-like statement,
3. or something happening in the situation being described.

Yes, Finnish word order is quite flexible.

The given sentence:

• Turvatarkastuksessa otan tietokoneen ja vesipullon pois käsimatkatavarasta.

This is a very natural order:

1. setting/context first: Turvatarkastuksessa
2. verb: otan
3. objects: tietokoneen ja vesipullon
4. direction/source phrase: pois käsimatkatavarasta

You could change the order for emphasis, for example:

• Otan turvatarkastuksessa tietokoneen ja vesipullon pois käsimatkatavarasta.
• Tietokoneen ja vesipullon otan pois käsimatkatavarasta turvatarkastuksessa.

These are grammatically possible, but the original sounds neutral and natural.

Vesipullo specifically means water bottle.

• vesi = water
• pullo = bottle

So:

• pullo = bottle
• vesipullo = water bottle

Finnish often uses compound words where English uses two separate words.

Likewise:

• tietokone = computer
• literally something like knowledge-machine

Not exactly.

• pois means away / off / out
• ulos means out(doors) / out to the outside

In this sentence, pois is the natural choice because the idea is removing something from inside the luggage.

Compare:

• otan kirjan pois laukusta = I take the book out of the bag
• menen ulos = I go outside

So pois fits removal, while ulos is more about movement to the outside.

You could, but the meaning would change.

• käsimatkatavara = hand luggage / carry-on baggage
• matkalaukku = suitcase

At airport security, käsimatkatavarasta is more precise if you mean the bag you take into the cabin and place on the belt.

So:

• pois käsimatkatavarasta = out of the carry-on bag
• pois matkalaukusta = out of the suitcase

Both are possible Finnish, but they refer to different luggage.

Yes, very likely.

Finnish often leaves possession unstated when it is obvious from context. In this situation, listeners naturally understand that the speaker means their own hand luggage.

If you wanted to make it explicit, you could say:

• pois käsimatkatavaroistani = out of my hand luggage / out of my carry-on items

But that sounds more specific and slightly heavier. The original sentence is simpler and very natural.

Because Finnish expresses that idea with a case ending instead of a separate preposition.

The ending -sta / -stä is the elative case, which means out of or from inside.

So:

• laukku = bag

• laukusta = out of the bag

• käsimatkatavara = hand luggage
• käsimatkatavarasta = out of the hand luggage

English uses separate words like from or out of, but Finnish often packs that meaning into the noun ending itself.