Learn Hardcore Finnish: Ystävä nauraa kovaa kahvilassa. - The friend laughs loudly in the café.

Context usually tells you whether the speaker means a specific friend or just some friend. The same applies to kahvilassa: it can be understood as in a café or in the café, depending on context.

How would I say my friend is laughing loudly in the café?

To add my, Finnish normally uses a possessive suffix (and often also a pronoun):

Ystäväni nauraa kovaa kahvilassa.
Minun ystäväni nauraa kovaa kahvilassa.

Both mean My friend is laughing loudly in the café.

Notes:

ystäväni = ystävä (friend) + -ni (my)
You can include minun for emphasis or clarity, but it is not always necessary if the context is clear.

What grammatical form is ystävä, and why does it look like that?

Ystävä is:

the nominative singular form of the noun (dictionary form),
and it is the subject of the sentence.

In Finnish, the subject is normally in the nominative singular when it is one person/thing. So:

Ystävä nauraa = The/A friend laughs.
If it were plural, it would be Ystävät nauravat = Friends laugh / The friends are laughing.

Why is there a verb like nauraa instead of something like is laughing with a separate to be verb?

Finnish doesn’t use a separate to be verb to form continuous tenses the way English does. The simple present tense verb nauraa covers both:

Ystävä nauraa = The friend laughs.
Ystävä nauraa = The friend is laughing.

Context decides whether you understand it as a general habit (laughs) or as something happening right now (is laughing). There is no special continuous form like English is laughing.

Is nauraa the dictionary form or the conjugated form? How can it be both?

Yes, nauraa is both:

the dictionary form (the basic infinitive), and
the 3rd person singular present tense form.

For this type of verb (ending in -aa / -ää), the 3rd person singular present looks identical to the infinitive:

infinitive: nauraa = to laugh
3rd person singular: hän nauraa = he/she laughs / is laughing

You know which one it is by context and by the sentence structure: if it comes after a subject like ystävä and there is no auxiliary, it’s the finite verb (laughs), not an infinitive (to laugh).

Could I add a pronoun and say Hän nauraa kovaa kahvilassa instead? What’s the difference from Ystävä nauraa kovaa kahvilassa?

Yes, you can say:

Hän nauraa kovaa kahvilassa. = He/She is laughing loudly in the café.

Differences:

Ystävä nauraa...: explicitly says a/the friend is laughing.
Hän nauraa...: uses a pronoun; you already know from context who he or she is.

Also, Finnish often drops subject pronouns if the subject is understood from context, but here ystävä is a full noun, so it’s present and not dropped.

What exactly is kovaa, and why isn’t it kovasti?

Kovaa comes from the adjective kova (hard, strong, loud). Here it’s used as an adverb, meaning loudly or hard (in the sense of strongly).

Grammatically:

kovaa is the partitive singular form of kova, commonly used with an adverbial meaning.
It’s very typical in Finnish that the partitive form of an adjective is used adverbially like this.

You could also say:

Ystävä nauraa kovasti kahvilassa.

Kovaa and kovasti are both correct; kovaa is very common in spoken and neutral language, kovasti can sound slightly more formal or just stylistically different. In many contexts they are interchangeable.

What case is kahvilassa, and what does the -ssa ending mean?

Kahvilassa is in the inessive case, which is formed with -ssa / -ssä and usually means in or inside something.

Breakdown:

kahvila = café (dictionary form)
kahvilassa = in the café

So the full sentence Ystävä nauraa kovaa kahvilassa literally means Friend laughs loudly in-the-café.

Why is it kahvilassa and not kahvilässä? How do I know whether to use -ssa or -ssä?

Finnish uses vowel harmony. The ending -ssa / -ssä changes according to the vowels in the word:

If the word has back vowels (a, o, u) and no front vowels (ä, ö, y) → use -ssa.
If the word has front vowels (ä, ö, y) → use -ssä.

Kahvila has a and i:

a is a back vowel
i is neutral (goes with either side)

So the correct form is:

kahvilassa (not kahvilässä)

If the noun were kylä (village), which has y and ä (front vowels), you’d say:

kylässä = in the village

Can the word order change? For example, can I say Kahvilassa ystävä nauraa kovaa?

Yes, Finnish word order is relatively flexible compared to English. All of these are grammatical:

Ystävä nauraa kovaa kahvilassa.
Kahvilassa ystävä nauraa kovaa.
Ystävä kahvilassa nauraa kovaa.

The basic neutral order is Subject–Verb–(Adverbials): Ystävä nauraa kovaa kahvilassa.

Changing the order usually changes the emphasis or what is treated as known vs. new information:

Kahvilassa ystävä nauraa kovaa.
Emphasises in the café: In the café, the friend is laughing loudly (as opposed to somewhere else).

The meaning (who laughs, where, how) stays the same; the pragmatic focus changes.

How do I say to the café and from the café, and how do they relate to kahvilassa?

Finnish uses different cases for in, to, and from:

kahvilassa = in the café (inessive -ssa / -ssä)
kahvilaan = to the café (illative, often -an / -en / -seen depending on the word)
kahvilasta = from the café (elative -sta / -stä)

Examples:

Ystävä nauraa kovaa kahvilassa.
The friend is laughing loudly in the café.
Ystävä menee kahvilaan.
The friend is going to the café.
Ystävä tulee kahvilasta.
The friend is coming from the café.

How would I make the sentence plural: Friends are laughing loudly in the café?

You change both the subject noun and the verb to the plural:

Ystävät nauravat kovaa kahvilassa.

Breakdown:

ystävät = plural nominative of ystävä (friends)
nauravat = 3rd person plural of nauraa (they laugh / are laughing)
kovaa and kahvilassa stay the same.

How do I negate the sentence: The friend is not laughing loudly in the café?

Finnish uses a special negative verb ei plus the main verb in a short form:

Ystävä ei naura kovaa kahvilassa.
= The friend is not laughing loudly in the café / The friend does not laugh loudly in the café.

Structure:

ystävä = subject
ei = negative verb (3rd person singular form of ei is just ei)
naura = negative stem of nauraa (no -a/ä at the end)
kovaa kahvilassa = adverbials (how and where)