Tänään tyttäreni laittaa sukkahousut hameen kanssa.

Finnish often shows possession with a suffix attached to the noun.

• -ni = my
• tytär = daughter
• tyttäreni = my daughter

So the sentence does not need a separate word like my in English, because that meaning is already built into tyttäreni.

Also, tytär is an irregular-looking noun type. Before a possessive suffix, it uses the stem tyttäre-, so you get tyttäreni, not tytärni.

Yes. Minun tyttäreni is also correct and means the same thing.

However, in Finnish, if the possessive suffix is already there, the pronoun minun is often left out:

• tyttäreni = my daughter
• minun tyttäreni = also my daughter, a bit more explicit

So in this sentence, tyttäreni is completely natural.

That is because some Finnish nouns, including tytär, use a stem that resembles the genitive when other endings are added.

Compare:

• tytär = daughter
• tyttären = of the daughter / the daughter’s
• tyttäreni = my daughter

So even though tyttäreni contains the stem tyttären-, here it is not a genitive meaning. It is just the normal possessive form of tytär.

In Finnish, sukkahousut is normally treated as a plural noun, just like some clothing words in English:

• housut = trousers/pants
• sukkahousut = tights/pantyhose

Even though it refers to one item of clothing, the form is plural. So sukkahousut is the normal dictionary form.

Here sukkahousut is the object of laittaa, and it is a total object: the daughter is putting on the tights as a complete item, not just “some tights” or an incomplete amount.

In Finnish, a plural total object usually looks like the nominative plural:

• Hän laittaa sukkahousut. = She puts on the tights.

If you used sukkahousuja, that would be the partitive plural, which usually suggests things like:

• an incomplete action
• an ongoing/unfinished action
• an indefinite amount
• or a negative sentence

For example:

• Hän ei laita sukkahousuja. = She does not put on tights.

Yes, in this sentence laittaa means something like put on.

The verb laittaa is very broad in Finnish. Depending on context, it can mean things like:

• put
• place
• set
• prepare
• put on

With clothes, laittaa can naturally mean put on. So here it refers to putting on the tights.

Other verbs are also possible in clothing contexts, but they are not exactly the same:

• käyttää = to wear/use
• pukea = to dress someone / to get dressed / to put clothes on

So laittaa works well here for the act of putting the clothing on.

Because kanssa requires the noun before it to be in the genitive.

• hame = skirt
• hameen = of the skirt / skirt’s / with the skirt (before kanssa)

So:

• hameen kanssa = with the skirt

This genitive form is caused by the postposition kanssa.

Because kanssa is a postposition, not a preposition.

English usually uses prepositions:

• with the skirt

Finnish often uses postpositions, which come after the noun:

• hameen kanssa

So the structure is literally closer to:

• the skirt’s with

That sounds strange in English, but it is normal Finnish grammar.

In a clothing context, hameen kanssa usually means with the skirt as part of the outfit.

So the idea is normally that the tights are being worn/put on with a skirt, not necessarily that both garments are put on at exactly the same moment.

Context decides the exact nuance, but in everyday usage this kind of phrase often describes what items go together.

Yes, the word order can change.

Finnish word order is more flexible than English word order. Putting tänään first gives it a natural topic or time-setting role:

• Tänään tyttäreni laittaa sukkahousut hameen kanssa.

This is a bit like saying:

• Today, my daughter is putting on tights with a skirt.

You could also say:

• Tyttäreni laittaa tänään sukkahousut hameen kanssa.

That is also correct. The difference is mainly about emphasis and information flow, not basic meaning.

Because Finnish has no articles.

English needs words like:

• a
• an
• the

Finnish normally does not use separate words for those meanings. The listener understands from context whether something is definite or indefinite.

So:

• tyttäreni can mean my daughter
• sukkahousut can mean the tights or just tights
• hameen kanssa can mean with a skirt or with the skirt, depending on context

Finnish relies much more on context than English does here.