Learn Hardcore Finnish: Opettaja merkitsi arvosanan todistukseen. - The teacher marked the grade on the report card.

opettaja = teacher
merkitsi = marked / recorded / entered (past tense of merkitä)
arvosanan = the grade (literally “grade” in object/genitive form)
todistukseen = into/onto the certificate / on the report (illative case: “into the certificate”)

A natural overall translation: “The teacher marked the grade on the certificate.”

Why is it merkitsi and not merkitsee?

merkitsee = present tense, 3rd person singular → he/she marks / is marking / means
merkitsi = past tense (imperfect), 3rd person singular → he/she marked / meant

So merkitsi is used because the action is in the past: “The teacher marked…”

What’s the basic form of merkitsi, and what does that verb mean in general?

The dictionary (infinitive) form is merkitä.

Its main meanings are:

to mark / note / record / enter
- Opettaja merkitsi arvosanan. = The teacher recorded the grade.
to mean / signify
- Mitä tämä sana merkitsee? = What does this word mean?

In your sentence, it’s clearly the first meaning: to record/enter a grade.

Why is it arvosanan and not just arvosana?

Arvosanan is the object form (genitive singular) of arvosana (grade, mark).

Nominative (basic form): arvosana
Genitive (also used as total object): arvosanan

In Finnish, a completed, whole object in a past event is usually in genitive:

Opettaja merkitsi arvosanan.
→ The teacher (successfully) marked the whole grade (finished action).

If it were arvosana (nominative) here, it would be ungrammatical. The verb merkitä needs its object in the appropriate object case, and for a completed single grade, that is arvosanan.

Could it be arvosanaa instead of arvosanan? What would change?

Yes, arvosanaa is the partitive form, and it would slightly change the meaning:

Opettaja merkitsi arvosanan todistukseen.
→ The teacher marked the (whole) grade on the certificate. (completed, result-focused)
Opettaja merkitsi arvosanaa todistukseen.
→ The teacher was (in the process of) marking a grade on the certificate.
It sounds incomplete or ongoing, with focus on the activity, not on a finished result.

In practice, with this verb and context, arvosanan (genitive object) is the normal and expected form.

Is arvosanan showing possession, like “someone’s grade”?

No. Here arvosanan is not possessive; it is simply the genitive object form of arvosana.

As an object:
- Opettaja merkitsi arvosanan. = The teacher marked the grade.
As a possessor, genitive usually comes before another noun:
- opiskelijan arvosana = the student’s grade
  (here opiskelijan is possessive: of the student)

You’d see a real possessive form on arvosana like this:

arvosanansa = his/her (own) grade
- Opettaja merkitsi arvosanansa todistukseen.
  → The teacher marked his/her own grade on the certificate (odd context, but grammatically correct).

So in the original sentence, arvosanan is just a normal total object, not possessive.

What case is todistukseen, and what does that ending mean?

Todistukseen is in the illative case, which often expresses movement “into / onto / to” something.

Base noun: todistus

Nominative: todistus = certificate, report, testimony
Illative singular: todistukseen = into the certificate / onto the certificate

Formally:

Stem: todistus → todistukse-
Illative ending: -en
Together: todistukse + en → todistukseen

So arvosanan todistukseen literally feels like “the grade into the certificate”, which we translate naturally as “on the certificate / onto the report”.

Why does Finnish use a case ending (todistukseen) instead of a preposition like “into” or “on”?

Finnish uses case endings where English mostly uses prepositions.

English: on the certificate, in the certificate, into the certificate
Finnish: todistuksessa (in / on the certificate, inessive),
todistukseen (into / onto the certificate, illative), etc.

In this sentence we have:

merkitä (jokin) johonkin = to mark (something) in/onto something
→ Opettaja merkitsi arvosanan todistukseen.
= The teacher marked the grade on the certificate.

So instead of saying “into the certificate” with a separate word, Finnish just changes the ending of todistus to todistukseen.

Can I change the word order, like Opettaja merkitsi todistukseen arvosanan?

Yes, that is also grammatically correct:

Opettaja merkitsi arvosanan todistukseen.
Opettaja merkitsi todistukseen arvosanan.

Both mean essentially the same thing. The neutral order is usually:

Subject – Verb – Object – Adverbials
Opettaja merkitsi arvosanan todistukseen.

Putting todistukseen earlier can slightly change the focus/emphasis, as if first setting the location (on the certificate) and then saying what was put there (the grade), but the meaning is still clear and natural.

Where are the English articles “the / a” in this sentence? How do I know if it’s “a grade” or “the grade”?

Finnish does not have articles like a/an or the.

opettaja can mean a teacher or the teacher
arvosana / arvosanan can mean a grade or the grade
todistus / todistukseen can mean a certificate or the certificate

Whether you translate as a or the depends on context:

In a specific school situation, you’d usually say:
- “The teacher marked the grade on the certificate.”
In a more generic statement, you might say:
- “A teacher marked a grade on a certificate.”

Finnish leaves this up to context rather than grammar.

What is the basic form and meaning of todistukseen / todistus?

The basic form is todistus.

Main meanings:

certificate / report / document
- school certificate, report card, course certificate, etc.
- koulutodistus = school certificate
proof / evidence / testimony
- todisteet ja todistus = evidence and testimony

In this sentence, given arvosanan (a grade), todistukseen clearly means a school report or certificate.

Can merkitsi here also mean “meant / signified,” like “The grade meant a lot to the student”?

The verb merkitä can indeed mean “to mean, to signify”, but in this sentence the structure tells us which meaning is intended.

merkitä jotakin jollekin = to mean something to someone
- Arvosana merkitsi paljon opiskelijalle.
  → The grade meant a lot to the student.
merkitä jokin johonkin = to mark/enter something into something
- Opettaja merkitsi arvosanan todistukseen.
  → The teacher marked the grade on the certificate.

Because the pattern here is “object (arvosanan) + illative (todistukseen)”, it clearly uses the “to mark/record” meaning, not the “to mean” meaning.

How would I say “The teacher has marked the grade on the certificate” (present perfect) in Finnish?

Use the Finnish perfect tense:

Opettaja on merkinnyt arvosanan todistukseen.

Breakdown:

on = auxiliary (3rd person singular of olla, to be/have)
merkinnyt = past participle of merkitä
Object and case stay the same: arvosanan todistukseen

This corresponds closely to English “has marked / has entered.”