Learn Hardcore Finnish: Tämä päivä oli kamala.

Saying Tänään oli kamala by itself is usually felt to be incomplete, because kamala is describing some implied noun (day, weather, situation, etc.) that you don’t name. You normally say:

Tänään oli kamala päivä.
Tänään oli kamalaa. (There was something horrible going on today – more vague / mass-like)

Why is the verb oli and not on?

oli is the past tense of olla (to be).

on = is
oli = was

So:

Tämä päivä on kamala. = This day is horrible. (right now)
Tämä päivä oli kamala. = This day was horrible. (you are talking about it after it happened)

Could I say Päivä oli kamala or Tämä oli kamala päivä instead? Do they mean the same thing?

All of these are grammatically correct, but with slightly different nuances:

Tämä päivä oli kamala.
This day was horrible. Neutral, a bit emphatic on “this day.”
Päivä oli kamala.
The day was horrible. You rely on context to know which day you mean (for example, the one you’ve just been talking about). Slightly more general.
Tämä oli kamala päivä.
Literally This was a horrible day. The focus is more on tämä (“this”), which could refer to “today” or to some specific day you are pointing at in a story or memory.

In everyday conversation, they often end up meaning almost the same, with context deciding which feels most natural.

Why is päivä in its basic form and not something like päivän?

päivä is in the nominative case, which is the basic dictionary form. In this sentence:

Tämä päivä is the subject.
Subjects in simple sentences are in the nominative: päivä (not päivän).

Finnish uses -n (genitive) in other roles, for example:

Kamalan päivän jälkeen. = After a horrible day.
Here päivän is genitive because of jälkeen (after), which requires the genitive.

But as the subject of “to be,” päivä stays in the nominative:

Päivä oli kamala.
Tämä päivä oli kamala.

Why is it kamala, not kamalan?

There are two common patterns to keep apart:

Predicative adjective (after to be):
- Päivä oli kamala. = The day was horrible.
  Here päivä (subject) and kamala (adjective) are both in nominative.
Attributive adjective (directly before a noun, and that noun is in some case):
- kamala päivä = a horrible day (nominative)
- kamalan päivän = of a horrible day (genitive; both words get -n because the day is genitive)

So in Tämä päivä oli kamala, the structure is:

subject: Tämä päivä (nominative)
verb: oli
predicative adjective: kamala (nominative to agree with the subject)

Kamalan would only appear if the noun is in the genitive (or some other case that requires agreement), not here.

What exactly does kamala mean? Is it as strong as horrible?

kamala means something like horrible, awful, terrible. It’s fairly strong, but in everyday speech it can also be used somewhat loosely, like English terrible or awful:

kamala päivä – a really bad day
kamala sää – horrible weather
Oli ihan kamalaa. – It was really awful.

Some near-synonyms:

hirveä – horrible, dreadful
kauhea – awful, terrible
tosi huono – really bad (more neutral / informal)

They can often be swapped with small nuances, but kamala is very common for describing a bad day or bad experience.

What’s the difference between tämä, tuo, and se?

They are all demonstrative pronouns/determiners (kind of like this/that in English):

tämä = this (one), close to the speaker
- Tämä päivä – this day
tuo = that (one), visible but not close to the speaker
- Tuo päivä – that day (over there / that one you’re looking at)
se = that/it, usually something already known from context or not necessarily visible
- Se päivä oli kamala. – That day was horrible.

In spoken Finnish, se is extremely common, sometimes where standard written Finnish might use tämä or a personal pronoun, but here Tämä päivä is the neutral written form for this day.

How do you pronounce Tämä päivä oli kamala?

Approximate pronunciation (IPA):

Tämä – [ˈtæ.mæ]
päivä – [ˈpæi̯.væ] (the äi is one syllable, like “eye” but starting with ä)
oli – [ˈo.li]
kamala – [ˈkɑ.mɑ.lɑ]

Whole sentence: [ˈtæ.mæ ˈpæi̯.væ ˈo.li ˈkɑ.mɑ.lɑ]

Key points:

Stress is always on the first syllable of each word: TÄ-mä PÄI-vä O-li KA-ma-la.
Single vowels (no double letters here) are short. Don’t lengthen them.
ä is a front vowel, like the “a” in cat but a bit cleaner; a is a back vowel, closer to the “a” in father.

Why is there no word for a or the in Tämä päivä oli kamala?

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

Definiteness and specificity are shown by:

context,
word choice (e.g. tämä already makes it specific: this day),
sometimes word order.

So Tämä päivä oli kamala can naturally be translated as This day was horrible, with English adding “this” and no separate articles needed.

Can I leave out tämä or päivä and still be correct?

You can change or omit parts, depending on what you want to say:

Päivä oli kamala.
The day was horrible. (Which day? Decided by context.)
Oli kamala päivä.
Literally There was a horrible day. In practice: It was a horrible day.
This is an existential structure and is very natural in Finnish.

What you generally can’t do is leave out päivä and only say:

Tämä oli kamala. – This was horrible.
This is grammatical, but now tämä refers to some situation/event, not “this day” specifically.
Tänään oli kamala. – feels incomplete; you’d normally say Tänään oli kamala päivä or Tänään oli kamalaa.

So yes, you can rearrange or drop words, but the meaning shifts slightly depending on what you keep.