Learn Hardcore Finnish: Ystäväni puhuu ruotsia äidinkielenään ja auttaa minua harjoittelemaan. - My friend speaks Swedish as a native language and helps me practice.

Using a possessive suffix:
- ystävä = friend
- ystäväni = my friend (friend + -ni “my”)
Using a possessive pronoun:
- minun ystäväni = my friend
  - minun = my
  - ystäväni still has the suffix -ni, so it literally means “my friend-my”.

In modern Finnish:

ystäväni alone is completely normal and often preferred in written language.
minun ystäväni is also correct, but can feel a bit heavier or more emphatic, like “my friend (as opposed to someone else’s)”.

In this sentence Ystäväni naturally means “My friend” thanks to the -ni suffix, so minun is not needed.

Why is ruotsia in the partitive case instead of ruotsi?

The verb puhua (to speak) usually takes the partitive when talking about languages:

puhua ruotsia = to speak Swedish
puhua suomea = to speak Finnish
puhua englantia = to speak English

Reasons:

Language as an “indefinite mass”
The partitive often marks something not counted or not complete. A language is treated like an uncountable mass: you “speak some Swedish”, not a specific, countable unit of it.
Fixed pattern
With languages, puhua + partitive is essentially a fixed, standard construction.

You can see puhua ruotsi in certain special contexts (like sports commentary referring to the Swedish language as a subject), but for “to speak Swedish (the language)”, the normal form is puhua ruotsia (partitive).

Why is ruotsia not capitalized like “Swedish” in English?

In Finnish, names of languages and nationalities are not capitalized:

ruotsi = Sweden
ruotsin kieli / ruotsia = Swedish (language)
suomi / suomea = Finnish (language)
englanti / englantia = English (language)

So:

puhuu ruotsia = speaks Swedish
puhuu suomea = speaks Finnish

The rule is: only proper names (countries, people, cities, etc.) are capitalized, not languages or demonyms. So the lowercase ruotsia is completely correct.

What exactly does äidinkielenään mean grammatically? How is it formed?

Äidinkielenään can be broken down like this:

äidinkieli = mother tongue (äidin = of mother, kieli = language/tongue)
stem: äidinkiele-
äidinkielenä = as (a) mother tongue (essive case, -nä)
äidinkielenään = as his/her/their mother tongue

So:

-nä = essive case, often translated as “as”
-än = 3rd person possessive suffix (his/her/their) attaching to the essive form

Function:

puhuu ruotsia äidinkielenään
= speaks Swedish as his/her/their mother tongue

So äidinkielenään tells you both:

The role/state: “as a mother tongue” (essive: -nä)
Whose mother tongue: “his/her/their” (possessive suffix: -än)

What is the difference between äidinkielenä and äidinkielenään?

äidinkielenä = as a mother tongue (no possessor explicitly marked)
äidinkielenään = as his/her/their mother tongue (possessive suffix -än)

In this sentence:

Ystäväni puhuu ruotsia äidinkielenään
clearly means “My friend speaks Swedish as their mother tongue”.

If you said:

Ystäväni puhuu ruotsia äidinkielenä

it sounds more general or slightly incomplete, as if you’re leaving out whose mother tongue it is. Native speakers strongly prefer äidinkielenään when you mean “as his/her mother tongue”.

What does the essive case (-nä as in äidinkielenään) actually do?

The essive case (-na / -nä) often corresponds to English “as” or describes a temporary role/state.

Examples:

opiskelen lääkärinä = I study as a doctor / I’m studying to be a doctor
työskentelen opettajana = I work as a teacher
lapsena = as a child / when (I was) a child

In äidinkielenään:

äidinkielenä = “as (a) mother tongue”
So puhuu ruotsia äidinkielenään literally: “speaks Swedish as (his/her) mother tongue.”

Why is it minua and not minut after auttaa?

Minua is the partitive form of minä; minut is the accusative form.

minä = I (nominative)
minua = me (partitive)
minut = me (accusative)

With auttaa (to help), the most usual object form for a person is partitive:

Hän auttaa minua. = He/She helps me.

Using minut with auttaa is possible but has a different nuance:

Hän auttaa minut ylös. = He/She helps me (up) – result: I end up in a new state/position.

So:

auttaa minua = helps me (in general, ongoing or unspecified)
auttaa minut X:ään = helps me into X (clear end result)

In your sentence, the meaning is general “helps me”, so minua (partitive) is natural.

Why is it harjoittelemaan and not just harjoitella?

Harjoittelemaan is the third infinitive in the illative case (often called the -maan / -mään form).

harjoitella = to practice (basic infinitive)
harjoittelemaan = “to (go and) practice”, “to practice” as a goal/purpose

The pattern here is:

auttaa + partitive object + 3rd infinitive illative (-maan / -mään)

So:

auttaa minua harjoittelemaan
= helps me (in order) to practice / helps me practice

This -maan/-mään form is very common after verbs that express:

movement: mennä nukkumaan = go to sleep
starting something: alkaa lukemaan (colloquial) = start reading
helping/teaching: auttaa minua harjoittelemaan, opettaa minua puhumaan

Can I drop minua and just say auttaa harjoittelemaan?

Yes, grammatically you can say:

Ystäväni auttaa harjoittelemaan.

This would be understood as “My friend helps (me/us/someone) to practice” from context. However:

Including minua makes it explicit that the friend is helping me.
Without minua, it’s more general or context-dependent: the friend helps with practicing.

In the original sentence, minua is natural and clear because we specifically want “helps me practice.”

Can I change the word order, for example: Ystäväni auttaa minua harjoittelemaan ja puhuu ruotsia äidinkielenään?

Yes. You can reorder the two coordinated parts:

Ystäväni puhuu ruotsia äidinkielenään ja auttaa minua harjoittelemaan.
Ystäväni auttaa minua harjoittelemaan ja puhuu ruotsia äidinkielenään.

Both are correct. The meaning is basically the same; the difference is which action you emphasize or mention first.

Finnish word order is relatively flexible, especially with coordinated clauses like these, as long as the forms (cases, endings) are correct.

Why is there no Finnish word for “he/she” in the sentence? How do we know it’s “his/her mother tongue”?

Finnish often omits subject pronouns when the verb form already shows who the subject is.

puhuu = “he/she speaks” (3rd person singular)
The subject is clear from context: Ystäväni (my friend).

For possession, Finnish normally uses possessive suffixes instead of a separate “his/her”:

äidinkieli = mother tongue
hänen äidinkielensä = his/her mother tongue
äidinkielenään (with -än) = as his/her/their mother tongue

In this sentence:

Ystäväni puhuu ruotsia äidinkielenään

The possessive suffix -än on äidinkielenään refers back to the understood 3rd person (ystäväni = my friend). So “he/she” and “his/her” don’t need to be written separately; they’re built into the verb and endings.