Varmistan, että puhelinnumero on oikein, ennen kuin soitan siskolleni.

I make sure that the phone number is correct before I call my sister.

Breakdown of Varmistan, että puhelinnumero on oikein, ennen kuin soitan siskolleni.

• minä: I
• olla: to be
• minun: my
• soittaa: to call
• sisko: the sister
• ennen kuin: before
• että: that
• oikein: correct
• varmistaa: to make sure
• -lle: to/onto
• puhelinnumero: phone number

Questions & Answers about Varmistan, että puhelinnumero on oikein, ennen kuin soitan siskolleni.

Why does the sentence start with Varmistan? What verb is it and what form?

Varmistan is the 1st person singular present tense form of the verb varmistaa (to make sure / to verify).

• Base form: varmistaa
• Conjugation: minä varmistan = I make sure / I verify
  Finnish often omits the subject pronoun minä because the verb ending already shows who is acting.

Why is there an että in the middle? What does it do?

että introduces a subordinate clause that functions like that... in English.
Here, Varmistan, että ... = I make sure that ...
Everything after että up to the comma is the content being checked.

Why is there a comma after Varmistan and another one before ennen kuin?

Finnish typically uses a comma to separate a main clause from a subordinate clause.

• Varmistan, että puhelinnumero on oikein, ...: comma before the että-clause
• ..., ennen kuin soitan siskolleni.: comma before the ennen kuin-clause
  These commas are very standard in written Finnish.

Is puhelinnumero the object of varmistaa? Why is it in basic form?

In the että-clause, puhelinnumero is actually the subject of on (is), not the object of varmistaa.
Structure of the subordinate clause:

• puhelinnumero = subject (the phone number)
• on = verb (is)
• oikein = complement (correct)
  So puhelinnumero stays in the nominative (dictionary) form because it’s the subject of that clause.

Why is it on oikein and not something like an adjective agreeing with puhelinnumero?

oikein here is used like a predicate expression meaning correct / right. In Finnish, predicate adjectives often appear in the nominative with olla (to be), and some words commonly used in this role look adverb-like. You will also see:

• Se on oikein. = That is correct.
• Puhelinnumero on oikea. = The phone number is correct.
  Both are possible, but on oikein is very natural in the sense of is correct / is right.

What does ennen kuin mean, and why does it require another verb?

ennen kuin means before (literally before than/that), and it introduces a time clause that contains its own verb.

• ennen kuin soitan ... = before I call ...
  Finnish uses a full clause after ennen kuin, not just an -ing form.

Why is it soitan and not soin or soittaa?

The verb is soittaa (to call / to ring / to play an instrument).

• Infinitive: soittaa
• 1st person singular present: soitan = I call
  soin would be from a different verb (soida, to ring/sound), so it would change the meaning.

What case is siskolleni, and why is it used for calling someone?

siskolleni is in the allative case (-lle), which often corresponds to to someone.

• sisko = sister
• siskolle = to (my) sister
• siskolleni = to my sister (allative + possessive suffix)
  With soittaa in the meaning to phone/call, Finnish commonly uses the allative: soittaa jollekin = to call someone.

What does the ending -ni in siskolleni mean? Why isn’t there a separate word for my?

-ni is the 1st person singular possessive suffix, meaning my. So:

• sisko = sister
• siskoni = my sister
• siskolleni = to my sister
  Finnish can express possession either with a suffix like -ni or with a genitive pronoun (minun siskolle), but the suffix is very common and often more natural.

Could I say ennen kuin minä soitan? Is omitting minä always okay?

Yes, ennen kuin minä soitan is grammatically correct.
Omitting minä is normal because soitan already shows it’s I. You typically add minä only for emphasis/contrast, for example:

• ... ennen kuin minä soitan, soitatko sinä? = ... before I call, will you call?

Why is the word order like this? Could I move parts around?

The given order is very neutral and natural: 1) Main clause: Varmistan
2) Content clause: että puhelinnumero on oikein
3) Time clause: ennen kuin soitan siskolleni

You can move the time clause to the front for emphasis:

• Ennen kuin soitan siskolleni, varmistan, että puhelinnumero on oikein.
  Both are correct; punctuation (commas) stays important.

Does Varmistan mean I am checking right now, or that I will check?

The present tense in Finnish often covers both present and near-future / general intention, depending on context. So Varmistan ... ennen kuin soitan ... naturally reads as a habitual or planned action: I make sure / I’ll make sure ... before I call ...
If you needed a clear past, you’d use varmistin (I made sure).