Sain ison yllätyksen, kun ystävä saapui ilman ilmoitusta.

I got a big surprise when a friend arrived without notice.

Breakdown of Sain ison yllätyksen, kun ystävä saapui ilman ilmoitusta.

• ystävä: the friend
• iso: big
• kun: when
• saada: to get
• saapua: to arrive
• ilman: without
• yllätys: the surprise
• ilmoitus: the notice

Questions & Answers about Sain ison yllätyksen, kun ystävä saapui ilman ilmoitusta.

What tense and person is sain?

Sain is the first person singular past tense (preterite) form of saada (“to get, receive”), so it means “I received” or “I got.”

Why does yllätys become yllätyksen?

Nouns ending in -s (like yllätys) form the accusative singular (object form) by changing -s to -ksen. That’s why the direct object is yllätyksen instead of ylllätys.

Why is the adjective iso inflected as ison?

Adjectives agree with their nouns in case and number. Since iso yllätys is the direct object in the accusative singular, both the noun and adjective take the accusative ending: ison yllätyksen.

Why isn’t there a subject pronoun like hän in “kun ystävä saapui”?

Finnish verbs include person information. Saapui is the 3rd person singular past tense, so the pronoun hän (“he/she”) is understood and usually omitted.

What does kun mean here, and could I use kunnes instead?

Here kun means “when,” introducing a time clause (“when my friend arrived”). Kunnes means “until,” so it would change the meaning to “until my friend arrived,” which isn’t intended here.

Why is ilman followed by ilmoitusta in the partitive?

The postposition ilman (“without”) governs the partitive case. Ilmoitus (“notification”) becomes ilmoitusta, yielding “without notification.”

Is saapui the same as tuli (“came”)?

Not exactly. Saapua specifically means “to arrive” (emphasizing reaching a destination), whereas tulla is a more general “to come.”

Can I change the word order of the sentence?

Yes. Finnish allows flexible word order. For example:
“Kun ystävä saapui ilman ilmoitusta, sain ison yllätyksen.”
It still means the same thing.

How would you say “without him letting me know” more explicitly?

You can use ilman että + clause:
“Sain ison yllätyksen, kun ystävä saapui ilman että hän ilmoitti.”
Here ilman että means “without (someone) doing something.”