Learn Hardcore Finnish: Mummo ja vaari istuvat keittiössä juomassa kahvia. - Grandma and grandpa sit in the kitchen drinking coffee.

informal, warm, everyday words, often used about or to your grandparents.
similar in tone to "gran" / "granny" / "grandma" and "grandpa" / "granddad" in English.

The more neutral or formal words are:

isoäiti = grandmother
isoisä = grandfather

So you could also say:

Isoäiti ja isoisä istuvat keittiössä juomassa kahvia.
That would sound a bit more formal or neutral; mummo ja vaari is homely and affectionate.

Why is the verb istuvat used, and how is it formed?

The base verb is istua = to sit.

Istuvat is:

present tense
3rd person plural (they)

Formation:

stem: istu-
personal ending for they: -vat (or -vät depending on vowel harmony)
→ istu-
- -vat = istuvat = they sit / they are sitting

Finnish has no separate continuous tense, so istuvat can mean both:

they sit in the kitchen (habitual / repeated)
they are sitting in the kitchen (right now)

Context usually tells which is meant. Here, with juomassa kahvia, it’s clearly “are sitting (now) drinking coffee.”

Why is there no word for "the" or "a" in the Finnish sentence?

Finnish has no articles (no equivalents of a/an or the).

So:

keittiössä can mean in a kitchen or in the kitchen.
kahvia can mean (some) coffee or coffee in general.

Whether you understand it as “a kitchen” or “the kitchen” depends on context:

If it’s the kitchen in their house that both speaker and listener know about, you’d naturally translate it as “in the kitchen.”
If you were deliberately talking about some unknown kitchen, you might choose “in a kitchen.”

The Finnish sentence itself doesn’t grammatically force one or the other.

What does keittiössä mean exactly, and what is the -ssä ending?

Keittiössä means “in the kitchen.”

Breakdown:

keittiö = kitchen
-ssä / -ssa = inessive case, meaning in, inside

So:

keittiö + ssä → keittiössä = in (the) kitchen

The inessive is used for:

being inside / within a place:
- talossa = in the house
- kaupungissa = in the city

Here it expresses location: where grandma and grandpa are sitting.

What is juomassa and how does it relate to juoda (“to drink”)?

The base verb is juoda = to drink.

Juomassa is:

the -MA infinitive (also called the third infinitive)
in the inessive case (-ssa / -ssä)

So:

juoda → juoma- (MA-stem) → juomassa

The construction istua + (MA-infinitive in -ssa) means:

to be in the middle of doing something while sitting
roughly: “sit (somewhere) doing X”

So:

istuvat keittiössä juomassa kahvia ≈ “they are sitting in the kitchen drinking coffee”
(literally: “they sit in the kitchen in-drinking coffee”)

This pattern works with many verbs:

He seisovat kadulla odottamassa bussia.
= They are standing on the street waiting for the bus.
Lapsi on huoneessa leikkimässä.
= The child is in the room playing.

Why do we say juomassa kahvia instead of just using a normal finite verb like juovat kahvia?

Both are possible, but they mean slightly different things.

Mummo ja vaari istuvat keittiössä juomassa kahvia.
- Focus: their state of sitting and what they are engaged in while sitting.
- Implies they are seated and currently in the activity of drinking coffee.
- Natural translation: “Grandma and grandpa are sitting in the kitchen drinking coffee.”
- Single scene: sitting + drinking as one situation.
Mummo ja vaari istuvat keittiössä ja juovat kahvia.
- Literally: “Grandma and grandpa sit in the kitchen and drink coffee.”
- Describes two actions side by side; still often understood similarly, but it’s less compact and can sound more like listing two facts.

The MA-infinitive + -ssa construction is very common in Finnish to express being in the middle of some activity connected to another verb like istua (sit), olla (be), seisoa (stand), käydä (go and do), etc.

Why is kahvia in that form, with -a at the end, instead of just kahvi?

Kahvia is partitive case of kahvi (coffee).

kahvi = coffee (nominative form)
kahvia = coffee (partitive form)

Partitive is used here mainly because:

It expresses an indefinite amount or “some” of something uncountable.
When you drink something, you usually drink some amount of it, not a whole counted unit.

So:

juoda kahvia = to drink (some) coffee
juoda vettä = to drink (some) water
syödä leipää = to eat (some) bread

Using kahvi (nominative) here would be ungrammatical; with juoda, the object is almost always in partitive unless you have a special contrastive or resultative meaning.

Is there any reason keittiössä and juomassa both have -ssa / -ssä? Are they the same case?

They both end with -ssa / -ssä, but they are slightly different uses of that ending.

keittiössä
- noun (keittiö) in the inessive case
- meaning: in the kitchen (location)
juomassa
- MA-infinitive of a verb (juoda) in the inessive
- meaning: in the middle of drinking / in drinking (coffee) (ongoing activity)

Grammatically, both are inessive case, but:

On a noun (keittiö) it marks physical location.
On a MA-infinitive (juoma-) it marks being in the process of that action, especially after verbs like istua, olla, käydä, etc.

So the same case ending serves two closely related but slightly different roles.

Could the word order be changed, for example: Keittiössä mummo ja vaari istuvat juomassa kahvia?

Yes, Finnish word order is fairly flexible, and that sentence is grammatically correct.

Mummo ja vaari istuvat keittiössä juomassa kahvia.
- Neutral, subject-first word order.
- Just stating what grandma and grandpa are doing.
Keittiössä mummo ja vaari istuvat juomassa kahvia.
- Puts keittiössä (in the kitchen) first, giving it extra emphasis.
- Often understood as contrasting with some other place:
  - “In the kitchen, grandma and grandpa are sitting drinking coffee (not, say, in the living room).”

There are many other acceptable variations, like:

Keittiössä istuvat mummo ja vaari juomassa kahvia. (focus on who is in the kitchen)
The basic meaning stays the same; word order mainly affects focus and emphasis, not core grammar.

How would I say “Grandma and grandpa are drinking coffee in the kitchen” without emphasizing the sitting part?

You could use a more straightforward structure with juovat (“they drink / are drinking”):

Mummo ja vaari juovat kahvia keittiössä.

This:

uses juovat (3rd person plural of juoda) as the main verb.
simply states that their activity is drinking coffee, and the location is in the kitchen.

Meaning-wise:

Mummo ja vaari istuvat keittiössä juomassa kahvia.
= They are sitting in the kitchen, engaged in drinking coffee.
Mummo ja vaari juovat kahvia keittiössä.
= They are drinking coffee in the kitchen (they might be sitting or standing; it’s not specified).

How do we know the sentence is happening now, since there is no separate “are sitting / are drinking” form in Finnish?

Finnish uses the simple present tense for several English meanings:

present continuous (“are sitting”, “are drinking”)
simple present (“sit”, “drink”)
sometimes habitual actions (“they (usually) drink coffee in the kitchen”)

Here:

istuvat ... juomassa kahvia is naturally read as a current ongoing scene, especially because:
- the MA-infinitive (juomassa) strongly suggests ongoing activity.

If you wanted to make habitual meaning explicit, you might add an adverb:

Mummo ja vaari usein istuvat keittiössä juomassa kahvia.
= Grandma and grandpa often sit in the kitchen drinking coffee.

Without an adverb, context normally tells you whether it’s “right now” or “in general.” In this sort of descriptive sentence, English speakers will usually interpret it correctly as “are sitting … drinking.”