Learn Hardcore Finnish: Minä herään joka yö.

Emphasise that it is I who wakes up (contrast with someone else):
- Minä herään joka yö, mutta hän nukkuu hyvin.
  = I wake up every night, but he sleeps well.
Sound a bit more explicit or careful (e.g. in beginner language, or in writing).

In everyday speech, especially spoken Finnish, people often just say Herään joka yö.

What is the dictionary form of herään, and how is this form built?

The dictionary (infinitive) form is:

herätä = to wake (up)

It is a so‑called type 4 verb (ending in -tä / -tä).
The present tense 1st person singular is formed like this:

Take the stem: herä-
Add the 1st person ending -n
There is a vowel change: herä-n → herä-en → herään (vowel combination contracts)

So you get:

minä herään = I wake (up)
sinä heräät = you wake (up)
hän herää = he / she wakes (up)
me heräämme = we wake (up)
te heräätte = you (pl.) wake (up)
he heräävät = they wake (up)

The form herään is specifically I wake (up).

Why is the present tense used for something that happens repeatedly, like every night?

In Finnish, the present tense is used for:

actions happening right now
habitual or repeated actions

So Minä herään joka yö means:

I wake up every night
(similar to English present simple with every / usually / always)

It does not force the meaning “right now”; context and adverbs (like joka yö) show that this is a regular, repeated event.

How would I say I woke up every night or I will wake up every night?

To talk about the past:

Minä heräsin joka yö.
= I woke up every night.

Here heräsin is the past tense (imperfect) of herätä in 1st person singular.

For the future, Finnish normally still uses the present tense, and the time reference comes from context:

Ensi viikolla herään joka yö.
= Next week I will wake up every night.

There is no separate future tense; you just use present herään, plus a future time expression like huomenna, ensi viikolla, etc.

What exactly does joka mean here, and how is it different from kaikki or jokainen?

In this sentence:

joka = every / each

Used with a singular noun:

joka yö = every night
joka päivä = every day
joka viikko = every week

Differences:

joka
- Means every / each
- Followed by a singular noun: joka yö
jokainen
- Also every / each (one), but more like every single individual
- Stands on its own or before a noun:
  - Jokainen herää joskus. = Everyone wakes up sometimes.
kaikki
- Means all
- Usually used with a plural noun or as a pronoun:
  - Kaikki yöt = all (the) nights
  - Herään kaikki yöt. = I wake up all nights (sounds a bit odd, but possible in some contexts)

In Minä herään joka yö, joka is the natural way to say every night.

Why is yö in its basic form without any ending? Why not yöllä or yötä?

Here the pattern is:

joka
- singular nominative (basic form)

So:

joka yö = every night
joka aamu = every morning
joka kuukausi = every month

Words like yöllä (adessive) or yötä (partitive) express different nuances:

yöllä = at night (in general, at that time)
- Herään yöllä. = I wake up at night. (no “every”)
yötä (partitive) appears in some expressions, e.g.
- valvoa yötä = to stay awake through the night

But with joka meaning every, you keep the noun in the basic singular form, so joka yö is correct.

Can I change the word order, like Joka yö herään or Herään minä joka yö? Does it change the meaning?

Yes, Finnish word order is fairly flexible, and the focus changes slightly:

Minä herään joka yö.
Neutral; maybe slight emphasis on I if context contrasts people.
Herään joka yö.
Very natural and neutral. Subject minä is understood from the verb.
Joka yö herään.
Emphasises joka yö (every night), something like:
- Every night I wake up (not just sometimes).
Herään minä joka yö.
Puts some emphasis on minä (I), often in contrast:
- I wake up every night (implying others don’t).

All of them can be correct, but Herään joka yö is the most typical everyday version.

What is the difference between herään and herätän? They look similar.

They are related but have different meanings:

herään
- From herätä = to wake up (intransitive)
- The subject wakes up themself.
- Minä herään joka yö. = I wake up every night.
herätän
- From herättää = to wake (someone) up (transitive)
- The subject causes someone else to wake up.
- Minä herätän hänet joka yö. = I wake him/her up every night.

So:

herään = I wake up
herätän = I wake someone (else) up

How do you pronounce yö, and what is that letter ö?

Pronunciation:

yö is one syllable: [yø̞]
The y is a front rounded vowel (like German ü).
- Try saying English ee (as in see) with your lips rounded like for oo.
ö is another front rounded vowel (like German ö, French eu in peu).
- Start from e as in bed, then round your lips.

So yö is not pronounced like English yo; both vowels are special Finnish vowels.

Is Minä herään joka yö formal, or is there a more colloquial way to say it?

In spoken, colloquial Finnish, you would often hear:

Mä herään joka yö.

Differences:

Minä → mä (spoken form)
herään stays the same in most dialects, though you might hear slightly reduced vowels in fast speech.

So:

Minä herään joka yö.
- Neutral, standard, good for writing and careful speech.
Mä herään joka yö.
- Very natural in everyday conversation.