Learn Hardcore Finnish: Unohdin salasanan, joten en voi kirjautua sisään. - I forgot the password, so I cannot log in.

Present 1sg: unohdan (I forget)
Past 1sg: unohdin (I forgot) Here, the past is formed with the -i past marker; 3rd person past is unohti, and adding the personal ending -n gives unohdin.

Why does "salasana" have -n (salasanan)? Is that genitive or accusative?

It’s a total object in the singular; in Finnish the singular accusative often looks like the genitive (ending -n). Unohdin salasanan = “I forgot the password” (a completed event affecting the whole object). So the form is genitive in shape but functions as the total/accusative object.

Could I say "Unohdin salasanani" to mean “I forgot my password”?

Yes. salasanani adds a possessive suffix meaning “my password,” making it explicit. Both are natural:

Unohdin salasanan (context usually implies it’s yours)
Unohdin salasanani (explicit “my”) You’ll also see the impersonal alternative Salasanani unohtui (“My password got forgotten”).

Can I use the partitive object, like "Unohdin salasanaa"?

Normally no. With unohtaa, a discrete item you fully forgot takes a total object (salasanan). A partitive (salasanaa) would suggest an ongoing, incomplete, or indeterminate action, which sounds odd here. Stick with salasanan (or salasanani).

Would "Olen unohtanut salasanan" be better than "Unohdin salasanan"?

Both are correct. Olen unohtanut salasanan (present perfect) stresses present relevance (“I have forgotten and still don’t remember”). Unohdin salasanan (simple past) states the past event. In help contexts, the perfect is very natural, but the past is also widely used (e.g., UI microcopy).

What does "joten" do here, and is the comma required?

joten means “so/therefore,” linking cause to result. Finnish puts a comma between independent clauses joined by conjunctions like joten, so the comma is required: Unohdin salasanan, joten….

How is "joten" different from "koska"?

joten = “so/therefore,” introduces the result: Unohdin salasanan, joten en voi kirjautua sisään.
koska = “because,” introduces the cause: En voi kirjautua sisään, koska unohdin salasanan. Both express cause–effect, but from opposite directions.

Why is it "en voi" and not "en voin"?

Finnish negation uses a special negative auxiliary that carries the person, while the main verb appears in a connegative form (no personal ending). So:

1sg negative: en
- voi
Compare positive: voin (“I can”) Other persons: et voi, ei voi, emme voi, ette voi, eivät voi.

Why "kirjautua" (infinitive) after "voi"?

The modal verb voida (“can, be able to”) takes the 1st infinitive of the main verb: voi kirjautua (“can log in”). Some other verbs, like pystyä, take the -maan/-mään form: en pysty kirjautumaan (sisään).

What exactly does "kirjautua" mean, and why "sisään"?

kirjautua is an intransitive/“self”-form derived from kirjata (“to register, record”), meaning “to register oneself” and, in IT, “to log in.” sisään (“in(wards)”) specifies direction; together kirjautua sisään = “log in.” Without sisään, it’s ambiguous or stylistically incomplete in this context.

How do I say “log out”?

Use the opposite directional adverb:

kirjautua ulos = log out Imperatives you’ll see on buttons:
Kirjaudu sisään / Kirjaudu ulos

What’s the difference between "kirjautua" and "kirjauttaa"?

kirjautua = intransitive: a user logs in themself.
kirjauttaa = transitive/causative: to log someone/something in (cause it to be logged). E.g., an admin might kirjauttaa a user in.

Could I say "sisälle" instead of "sisään"?

For logging in, sisään is the standard choice. sisälle can indicate movement “to the inside (space)” and is common with physical movement; with IT login, stick to sisään.

Is "En muista salasanaa" acceptable instead of "Unohdin salasanan"?

Yes. En muista salasanaa = “I don’t remember the password,” describing a current state. Unohdin salasanan highlights the forgetting event. Both justify the result en voi kirjautua sisään.

Are there synonyms for "joten" here?

Yes, depending on style:

siksi (“that’s why”): Unohdin salasanan. Siksi en voi kirjautua sisään.
niinpä (“so, hence”): Unohdin salasanan, niinpä en voi… (a bit more idiomatic/informal).
sen takia/tämän vuoksi (“because of that/this”): more formal.

Pronunciation tips for the tricky bits?

joten: initial stress, j like English y in “yes.”
kirjautua: syllables kir-jau-tua; au is one diphthong [au]; don’t insert extra vowels.
sisään: long ää; keep it clearly lengthened.