Learn Hardcore Finnish: Teen kotitehtävän valmiiksi illalla.

actions happening now:
- Teen kotitehtävän. – I am doing the homework.
planned or certain future actions:
- Teen kotitehtävän illalla. – I will do the homework in the evening.

The future meaning comes from context and time expressions like illalla (in the evening), not from the verb ending. So teen can mean “I do / I am doing / I will do” depending on context.

Why is it kotitehtäväN and not just kotitehtävä?

Kotitehtävä is the basic form (nominative) meaning “homework / home assignment”.
Here we see kotitehtäväN, which is the genitive singular.

In this sentence, kotitehtävän is a total object – the whole homework will be completed. In Finnish, a completed, definite object normally appears in the genitive singular:

Teen kotitehtävän. – I (will) do / finish the homework. (all of it)
Luen kirjan. – I (will) read the book (from start to finish).

So the -n on kotitehtävä marks it as a completed object, not as a possessive or anything else here.

What does valmiiksi add? Could I just say Teen kotitehtävän illalla?

You can say Teen kotitehtävän illalla, and it is perfectly good Finnish. It already usually implies you’ll get it done.

Valmiiksi makes the result very explicit:

valmis = ready
valmiiksi = into a ready state / to completion

So:

Teen kotitehtävän illalla.
– I’ll do my homework in the evening. (normally understood as finishing it, but not emphasized)
Teen kotitehtävän valmiiksi illalla.
– I’ll get my homework completely finished in the evening.

Valmiiksi makes it sound like you’re focusing on the completion rather than just the activity of doing homework.

What is the ending -ksi in valmiiksi?

The -ksi ending is the translative case. It often expresses a change of state or the result of an action.

Some examples:

maalata seinä punaiseksi – to paint the wall red (change to a red state)
tulla lääkäriksi – to become a doctor
leikata hiukset lyhyiksi – to cut hair short

Here:

valmis (ready)
valmiiksi (into a ready state, to completion)

So valmiiksi shows that the action of doing the homework results in it being ready / finished.

How does valmiiksi affect the case of kotitehtävän?

The idea of completion / result (often expressed with valmiiksi) encourages the use of a total object, which in the singular is genitive -n.

Teen kotitehtävän valmiiksi.
– I will finish the homework. (one specific homework, completed → genitive)

If the action is ongoing / incomplete / just some of something, you typically see the partitive:

Teen kotitehtävää illalla.
– I (will be) doing homework in the evening. (process, not necessarily finishing)

So valmiiksi strongly suggests a completed result, matching with the genitive object kotitehtävän.

Could I use the plural and say Teen kotitehtävät valmiiksi illalla? What’s the difference?

Yes, that is possible, but the meaning changes slightly.

Teen kotitehtävän valmiiksi illalla.
– I’ll finish the homework (one specific assignment) in the evening.
Teen kotitehtävät valmiiksi illalla.
– I’ll finish the homeworks / all the homework tasks in the evening.

In practice:

kotitehtävä: often one assignment, or “my homework” as a unit
kotitehtävät: several tasks, or “all the homework tasks”

You’ll also commonly hear:

Teen läksyt illalla. – I’ll do my homework in the evening.
(läksyt is a very common everyday word for “homework”, usually plural.)

What’s the difference between Teen kotitehtävän illalla and Teen kotitehtävää illalla?

This is the difference between total and partial / ongoing object:

Teen kotitehtäväN illalla. (genitive)
- I will do / finish the homework in the evening.
- You’re talking about one specific homework, and you’re presenting it as completed.
Teen kotitehtäväÄ illalla. (partitive)
- I (will be) doing homework in the evening.
- Focus on the activity / process, not on finishing.
- Maybe you’ll only do part of it, or you don’t say whether you finish.

Finnish uses object case to show this kind of nuance, which English usually shows with adverbs or context.

Why is it illalla? What does the -lla ending mean here?

Ilta = evening.
Illalla is ilta + lla, the adessive case.

With times of day, -lla/-llä often means “at that time, during that time”:

aamulla – in the morning
päivällä – in the daytime
illalla – in the evening
yöllä – at night

So illalla is best translated as “in the evening” or “this evening / in the evening (in general)”, depending on context.

Could I say Illalla teen kotitehtävän valmiiksi? Does the word order change the meaning?

Yes, that word order is correct:

Teen kotitehtävän valmiiksi illalla. (neutral, subject–verb–object–adverb)
Illalla teen kotitehtävän valmiiksi. (time expression first)

The basic meaning stays the same: you’ll finish your homework in the evening.

Putting Illalla first tends to emphasize the time:

“In the evening I’ll finish my homework (not now / not in the morning).”

Finnish word order is flexible; changes mostly affect emphasis / focus, not core grammar.

Why is there no minä (“I”) in the sentence? Is Teen kotitehtävän valmiiksi illalla less personal than Minä teen…?

The person is shown on the verb ending, so the subject pronoun is often dropped when it’s obvious:

Teen kotitehtävän. – I (will) do the homework.
Teet kotitehtävän. – You (will) do the homework.
Hän tekee kotitehtävän. – He/She (will) do the homework.

You can include the pronoun for emphasis or contrast:

Minä teen kotitehtävän valmiiksi illalla.
– I will finish the homework in the evening (implying maybe others won’t).

So Teen kotitehtävän valmiiksi illalla is completely natural and not less “personal”; it’s just normal Finnish style.

Why is the verb tehdä conjugated as teen and not something like tehen or teden?

Tehdä (“to do, to make”) is irregular. Its stem in many present-tense forms is tee-, not teh-:

minä teen
sinä teet
hän tekee
me teemme
te teette
he tekevät

The infinitive shows tehdä, but when conjugated, the h disappears in these forms and you see tee- or teke- as the stem.

So teen is simply the correct 1st person singular present form of tehdä.