Learn Hardcore Finnish: Minulla on tapana juoda kahvia aamulla, ja useimmiten luen samalla uutisia. - I have a habit of drinking coffee in the morning, and most often I read the news at the same time.

Minä olen tapa(na) would mean something like I am a habit, which is wrong here.
So Minulla on tapana fits the normal Finnish pattern Minulla on X = I have X.

Why is it tapana and not tapa in Minulla on tapana juoda kahvia?

Tapana is the essive case of tapa (habit).

The expression olla tapana is a fixed pattern that means to be a habit (for someone):

Minulla on tapana juoda kahvia
literally: On me is as a habit to drink coffee
meaning: I have a habit of drinking coffee / I usually drink coffee.

Here:

tapa (habit) → tapana (essive) = as a habit
The person whose habit it is is in the adessive: minulla.

You generally learn olla tapana tehdä jotakin as a set structure:

Minulla on tapana mennä nukkumaan aikaisin.
Heillä on tapana matkustaa kesällä.

Why is it juoda kahvia and not juon kahvia or juoda kahvi?

Why juoda (infinitive) and not juon (finite verb)?
After olla tapana, the action that is the habit is usually in the basic infinitive:

Minulla on tapana juoda kahvia. = I have a habit of drinking coffee.

So: olla tapana + infinitive.

Why kahvia and not kahvi?
Kahvia is the partitive form of kahvi:

With juoda (to drink), the object is normally in the partitive when you mean an indefinite amount of a drink:
- Juon kahvia. = I drink (some) coffee.
- Juon vettä. = I drink (some) water.

So juoda kahvia = to drink coffee (some coffee, not a specific “one whole coffee”), which is the normal way to say it in Finnish.

Why is kahvia in the partitive and not kahvin or kahvi?

Kahvia is partitive singular. You get the partitive object here because:

It is an unspecified, not‑counted amount of a mass noun (coffee).
Drinks and foods in this kind of general statement usually take the partitive with verbs like juoda, syödä:

Examples:

Juon kahvia. = I drink coffee (in general / some coffee).
Syön leipää. = I eat bread.

If you said juoda kahvin, that would normally mean to drink the (one) coffee (a specific one, e.g. a cup in front of you), which is a different nuance.

Why is it aamulla and not aamu or aamuna?

Aamulla is the adessive case of aamu (morning).

Adessive (-lla / -llä) is very often used for time expressions meaning at / in:

aamulla = in the morning
iltapäivällä = in the afternoon
yöllä = at night

So juoda kahvia aamulla = to drink coffee in the morning.

Aamu alone would just mean morning as a bare noun.
Aamuna (essive) would be more like as a morning, on a (particular) morning, used in more specific or literary contexts, not for the everyday in the morning time phrase.

Could you also say aamuisin instead of aamulla, and is there a difference?

Yes, you could.

aamulla = in the morning (a typical morning time, or on a specific morning depending on context)
aamuisin = in the mornings, on mornings (habitually, repeatedly)

In this sentence, which describes a habit, both are natural, but:

Minulla on tapana juoda kahvia aamuisin
slightly emphasizes the habitual, every‑morning nature even more.

Aamulla can still describe a habitual situation here because the whole structure on tapana already encodes a habit.

What exactly does useimmiten mean, and where can it go in the sentence?

Useimmiten means most often, usually, for the most part.

In this sentence:

ja useimmiten luen samalla uutisia.
= and most often I read the news at the same time.

Position is fairly flexible:

Useimmiten luen samalla uutisia.
Luen useimmiten samalla uutisia.

Both are possible. Placing useimmiten early tends to emphasize the frequency:

Useimmiten luen samalla uutisia. (Most often, I read the news at the same time.)

The original position before luen is very normal and neutral.

What does samalla literally mean, and why does it mean “at the same time” here?

Samalla comes from sama (same) + the adessive ending -lla.

Literally: on the same (thing/occasion) → idiomatically: at the same time / simultaneously.

In this sentence:

luen samalla uutisia = I read the news at the same time (as I’m drinking coffee).

It is used very commonly as an adverb:

Tehdään se samalla. = Let’s do it at the same time / while we’re at it.
Samalla voimme puhua suunnitelmista. = At the same time we can talk about the plans.

Why is it uutisia and not uutiset or uutisiaan?

Uutisia is partitive plural of uutinen (news item) / uutiset (the news as a whole).

Partitive plural
- uutisia = some news, news items (indefinite, not a closed set)
- This fits the idea of reading (some) news in general.
Why not uutiset?
- luen uutiset = I read the (whole) news, all of them (more like a complete set).
- luen uutisia = I read news / read some news items (more open‑ended and natural for a habitual statement).
Why not uutisiaan?
- -aan/-ään would mark a third‑person possessive (his/her/their news).
- Here, we just mean news in general, with no possessor, so simple uutisia is correct.

Why is there no minä before luen? How do we know it still means I read?

Finnish is a pro‑drop language: subject pronouns are usually omitted because the verb ending already shows the person.

luen ends with -n → 1st person singular → I read.

So both of these mean the same:

Minä luen samalla uutisia.
Luen samalla uutisia.

Using minä adds emphasis on the subject:

(Minä) luen samalla uutisia, mutta hän kuuntelee musiikkia.
(I read the news, but he listens to music.)

In neutral statements, the pronoun is often left out.

Why is there a comma before ja in aamulla, ja useimmiten luen samalla uutisia?

In Finnish, you normally put a comma between two independent clauses, even if they are joined by ja (and).

Here we have two main clauses:

Minulla on tapana juoda kahvia aamulla
useimmiten luen samalla uutisia

They are both complete clauses with their own verbs (on, luen), so a comma before ja is normal:

Minulla on tapana juoda kahvia aamulla, ja useimmiten luen samalla uutisia.

This is different from English, where we often omit the comma in I do X and I do Y.

Can the word order in the second part change, for example Useimmiten luen uutisia samalla? Does it change the meaning?

Yes, Finnish allows several word orders, and the basic meaning stays the same, but the emphasis shifts slightly.

Possible variants:

ja useimmiten luen samalla uutisia. (original)
Fairly neutral; slight focus on often
- at the same time.
ja useimmiten luen uutisia samalla.
Similar meaning; might sound a bit more like the focus is on reading news and also at the same time.
ja luen useimmiten samalla uutisia.
Emphasizes that it is most often that you read news in that situation.

All of them are understandable and grammatical. Finnish tends to keep the verb relatively early, but there is flexibility for emphasis and rhythm.

Could you say Minulla on tapa juoda kahvia aamulla, or is tapana required?

Minulla on tapa juoda kahvia aamulla is grammatically possible and understandable, but it sounds less idiomatic than Minulla on tapana juoda kahvia aamulla.

Nuance:

Minulla on tapa juoda kahvia aamulla.
= I have a habit / a way of drinking coffee in the morning.
Slightly more concrete, could even be heard as “I have this particular way of drinking coffee”.
Minulla on tapana juoda kahvia aamulla.
= It is my habit to drink coffee in the morning.
This is the standard idiomatic way to express a personal habit.

So for describing a general habit, olla tapana + infinitive is what you usually want.

Are there other common ways to say “I usually drink coffee in the morning” in Finnish, and how do they differ from Minulla on tapana juoda kahvia aamulla?

Yes, some common alternatives:

Yleensä juon kahvia aamulla.
- Very direct: I usually drink coffee in the morning.
- Uses adverb yleensä (usually).
- Less “formal‑sounding” than on tapana, very common in speech.
Usein juon kahvia aamulla.
- I often drink coffee in the morning.
- Slightly weaker than usually; more like often.
Olen tottunut juomaan kahvia aamulla.
- I am used to drinking coffee in the morning.
- Focus on being accustomed to it, not just frequency.
Minulla on tapana juoda kahvia aamulla.
- Emphasizes a characteristic habit of yours.
- Slightly more formal or “statement‑like”, but very natural in both speech and writing.