Minä ostan lipun elokuvaan.

I buy a ticket to the movie.

Breakdown of Minä ostan lipun elokuvaan.

• minä: I
• ostaa: to buy
• elokuva: the movie
• lippu: the ticket

Questions & Answers about Minä ostan lipun elokuvaan.

Why is Minä used here, and can I leave it out?

In Finnish, verbs are conjugated for each person, so the subject is normally clear from the verb ending. Minä means “I” and is optional. You include it for emphasis or clarity. In everyday speech you’d usually say simply:
Ostan lipun elokuvaan.

What does ostan mean, and how is it formed?

Ostan is the first-person singular present tense of the verb ostaa (“to buy”).
• ostaa = infinitive (“to buy”)
• drop -a/a from the infinitive → ost-
• add the -an ending for “I” → ostan (“I buy” / “I am buying”)

Why is lipun not lippu?

Lippu is the nominative form (“a ticket” as a subject). Here it’s a specific, complete object of the verb, so Finnish marks it with -n (the so-called accusative/genitive object form).
• nominative (subject): lippu
• accusative/genitive (singular, complete object): lipun

When would I use lippua instead of lipun?

Lippua is the partitive singular. You use the partitive to express:
• an incomplete action (e.g. “I’m buying some ticket(s)”)
• an unspecified quantity (“some ticket”)
• ongoing, habitual actions
If you want to say “I’m buying a ticket” as a complete transaction, you use lipun. If you just mean “I’m buying some tickets” in general, you’d say ostan lippuja (partitive plural).

What case is elokuvaan, and why is it used here?

Elokuvaan is the illative singular of elokuva (“movie”), marked by -an. The illative denotes movement into or towards something. So elokuvaan means “into/to the movie,” i.e. “for the movie” in the sense of entering the screening.

Could I say Minä ostan elokuvalipun instead?

Yes, you can form a compound noun elokuvalippu (“movie ticket”) and say Minä ostan elokuvalipun. In that case:
• elokuvalippu (compound) becomes elokuvalipun in the accusative/genitive (complete object)
Both sentences are correct; the original stresses the destination (elokuvaan), this one focuses on the type of ticket.

How do I turn this into a question: “Am I buying a ticket to the movie?”

In Finnish you invert the verb and subject and add -ko/-kö to the verb. Often you drop Minä.
Ostan lipun elokuvaan → Ostanko lipun elokuvaan?

How would I say “I’m buying tickets to the movies” (plural)?

You’d pluralize both lippu and elokuva. Since you’re specifying multiple complete tickets and multiple movies, use the accusative/genitive plural -t on lippu and the illative plural -in on elokuva:
Ostan liput elokuviin.