Opettaja selitti asian loistavasti.

The teacher explained the matter excellently.

Breakdown of Opettaja selitti asian loistavasti.

• selittää: to explain
• opettaja: the teacher
• asia: the matter
• loistavasti: great

Questions & Answers about Opettaja selitti asian loistavasti.

What are the grammatical roles of each word in Opettaja selitti asian loistavasti?

• Opettaja – subject (nominative singular): the/a teacher
• selitti – main verb (3rd person singular, past tense) from selittää: explained
• asian – object (genitive/“total object”) from asia: the matter / the thing
• loistavasti – adverb: brilliantly, excellently

So the basic structure is Subject – Verb – Object – Adverb (SVO + adverbial).

Why is it opettaja and not something like opettajan?

Opettaja is in the nominative case, which is the default form for the subject of a sentence.

• Dictionary form: opettaja (teacher)
• Genitive (e.g. of the teacher): opettajan

In this sentence, opettaja is the one doing the action (explaining), so it stays in the nominative:
Opettaja selitti… = The teacher explained…

What tense and person is selitti, and what is the base verb?

The base verb (dictionary form) is selittää (to explain).

selitti is:

• past tense (imperfect)
• 3rd person singular (he/she/it or the teacher)

Rough pattern:

• minä selitin – I explained
• sinä selitit – you explained
• hän / opettaja selitti – he/she/the teacher explained
• me selitimme – we explained
• te selititte – you (pl.) explained
• he selittivät – they explained

Why does the verb change from selittää to selitti? What’s going on with the spelling?

Two main things happen when forming selitti from selittää:

1. Vowel length change

   • Infinitive: selit-tää (long ää)
   • Past 3rd person: selit-ti (short i)

2. Personal ending is added

   • The past tense marker is -i- and the 3rd person singular ending is (no extra ending), so you effectively get selit + ti → selitti.

You don’t need to think too deeply about the phonology at first; just learn that selittää → selitti is the regular past-tense pattern for this verb type.

Why is the object asian and not asia or asiaa?

asian is the genitive form of asia:

• nominative: asia – a/the matter
• genitive: asian – of the matter (and also used as a “total object”)

In object position, Finnish often uses:

• genitive form (asian) for a complete, bounded object
• partitive form (asiaa) for an incomplete, ongoing, or unbounded object

Here, Opettaja selitti asian loistavasti implies that the teacher explained the whole matter, completely and successfully. So the “total” object is marked with asian.

How would the meaning change if it were Opettaja selitti asiaa loistavasti?

Opettaja selitti asiaa loistavasti uses asiaa (partitive) instead of asian (genitive).

Nuance:

• selitti asian – explained the whole thing / got through it fully
• selitti asiaa – was explaining the matter (activity in progress, not necessarily completed, or focusing on the process rather than the finished result)

In English you might feel a contrast like:

• The teacher explained the matter brilliantly. (done, complete)
• The teacher was explaining the matter brilliantly. (describing the ongoing action)

Why is it asian and not asiasta (about the matter)? Don’t some verbs use -sta/-stä?

Yes, some verbs in Finnish require -sta/-stä (from/about X), but selittää does not. It takes a direct object, not an “about”-phrase.

Compare:

• selittää asian – to explain the matter (direct object)
• kertoa asiasta – to tell about the matter (elative case -sta)

So:

• With selittää, you say asian (object).
• With kertoa, you’d say asiasta (about the matter).

What exactly is loistavasti, and how is it formed?

loistavasti is an adverb meaning brilliantly, excellently.

It is formed from the adjective loistava (brilliant, excellent) by adding the adverbial suffix -sti:

• loistava (adj.) → loistavasti (adv.) – brilliant → brilliantly

This -sti ending is a regular way to form adverbs from adjectives:

• hyvä → hyvin (good → well, irregular)
• nopea → nopeasti (fast → quickly)
• selvä → selvästi (clear → clearly)

Can loistavasti go in other positions in the sentence, or must it be at the end?

loistavasti is flexible in word order. All of these are possible:

• Opettaja selitti asian loistavasti.
• Opettaja selitti loistavasti asian. (focus a bit more on how it was explained)
• Opettaja loistavasti selitti asian. (emphasizes the manner even more)

The basic neutral word order is with loistavasti at the end, but Finnish allows reordering to highlight different parts of the sentence. The meaning stays essentially the same; the emphasis shifts slightly.

Why are there no words for a or the in opettaja and asian?

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

Context tells you whether you should understand opettaja as:

• a teacher (new, non-specific)
• the teacher (already known in the context)

Similarly, asian can be the matter or the thing depending on context. The Finnish forms themselves don’t change for definiteness; they only show case/number, not a/the.

How would I make this sentence negative?

To negate, Finnish uses the negative verb ei plus the past participle of the main verb, and the object usually switches to partitive.

Affirmative:

• Opettaja selitti asian loistavasti.

Negative (neutral):

• Opettaja ei selittänyt asiaa loistavasti.
  → The teacher did not explain the matter brilliantly.

Changes:

• selitti → ei selittänyt (negative + past participle)
• asian → asiaa (object usually becomes partitive under negation)

Could I replace asian with a pronoun like sen? How would that look?

Yes. sen is the 3rd-person singular pronoun in the genitive form (from se).

You can say:

• Opettaja selitti sen loistavasti.
  → The teacher explained it brilliantly.

Here:

• sen is functioning like asian: a total object referring to some previously mentioned thing.
• It’s very natural when the matter has already been named, and you don’t want to repeat asia.