Learn Hardcore Icelandic: Ég er þakklát fyrir vináttuna okkar, þó að við búum í mismunandi löndum. - I am grateful for our friendship, even though we live in different countries.

Ég er þakklát – used if the speaker is female (feminine singular nominative).
Ég er þakklátur – used if the speaker is male (masculine singular nominative).
Ég er þakklátt – used for neuter subjects (e.g. with a neuter noun).

So the form þakklát tells us that the speaker is female in this sentence. A man would say:

Ég er þakklátur fyrir vináttuna okkar ...

What does fyrir do here, and why is it vináttuna and not just vinátta?

fyrir is a preposition that often corresponds to English for or because of.

When fyrir has the meaning “for (something), on account of (something)”, it normally takes the accusative case.

Base noun: vinátta – friendship (nominative, indefinite)
Definite form (nominative): vináttan – the friendship
Definite, accusative singular (feminine): vináttuna

Because fyrir wants the accusative object here, and the friendship is definite (our friendship, a specific one), we get:

fyrir vináttuna okkar
for our friendship

Why is it vináttuna okkar and not okkar vinátta for “our friendship”?

Both are grammatically possible, but they are used a bit differently:

vináttuna okkar
- Noun + definite ending (-na) + possessive pronoun after it
- Very common for something concrete and specific
- Literally: the friendship our → “our friendship” (this specific one)
okkar vinátta
- Possessive pronoun before the noun, noun without definite ending
- Feels a bit more abstract or contrastive, like “our friendship (as opposed to others’)”

In this sentence, you are talking about the particular friendship between you and the other person, so vináttuna okkar is the most natural choice.

What exactly does þó að mean here, and is the comma before it necessary?

þó að is a subordinating conjunction meaning although / even though.

Ég er þakklát fyrir vináttuna okkar, þó að við búum í mismunandi löndum.
→ I am grateful for our friendship, even though we live in different countries.

The comma marks the boundary between the main clause (I’m grateful…) and the subordinate clause (though we live…). In modern Icelandic writing:

A comma before a conjunction like þó að that introduces a clause like this is standard and recommended.

Shouldn’t the verb after þó að be in the subjunctive? Is búum subjunctive or indicative here?

After þó að (although/even though), Icelandic usually uses the subjunctive.

For the verb búa (to live, reside), 1st person plural present indicative and subjunctive happen to look the same:

við búum – “we live / we reside”
- Formally this can be indicative or subjunctive, depending on context.

So in this sentence:

After þó að, búum is understood as subjunctive, even though it looks like the indicative. The form just happens to be identical in this person/tense.

Why is it í mismunandi löndum and not í mismunandi lönd?

The preposition í can take accusative or dative, depending on meaning:

í
- accusative → movement into something
  - e.g. Ég fer í landið. – I go into the country.
í
- dative → location / state in something
  - e.g. Ég bý í landinu. – I live in the country.

Here, the meaning is “in different countries” as a location, so í takes the dative plural:

Nominative plural: lönd – countries
Dative plural: löndum – in countries

Hence: í mismunandi löndum.

Does mismunandi change form to agree with löndum?

No. mismunandi is (in modern use) an indeclinable adjective. It keeps the same form in all genders, numbers, and cases:

mismunandi lönd – different countries (nom./acc. pl.)
í mismunandi löndum – in different countries (dat. pl.)
mismunandi fólk – different people (neuter singular)
mismunandi bækur – different books (fem. pl.)

So you don’t see a special dative plural form like *mismunöndum; it always stays mismunandi.

Why do we use búa for “live” here and not lifa?

Icelandic has two common verbs that can translate English “live”:

búa – to live/reside somewhere, to have one’s home
- Ég bý í Reykjavík. – I live in Reykjavík.
- Við búum í mismunandi löndum. – We live in different countries.
lifa – to live, be alive, to be alive through something, or live (a certain way)
- Hann lifir enn. – He is still alive.
- Hún lifir hamingjusömu lífi. – She lives a happy life.

Since the sentence is about where people reside, búa is the correct verb: við búum í mismunandi löndum.

How would the sentence change if I (the speaker) were a man?

Only the adjective agreeing with Ég changes gender; the rest stays the same:

Female speaker:
Ég er þakklát fyrir vináttuna okkar, þó að við búum í mismunandi löndum.
Male speaker:
Ég er þakklátur fyrir vináttuna okkar, þó að við búum í mismunandi löndum.

Everything else (cases, word order, verbs) remains identical.

Can I drop að and just say þó við búum í mismunandi löndum?

In spoken Icelandic, many speakers do indeed drop að and say:

…þó við búum í mismunandi löndum.

This is quite natural in conversation.

In careful or formal writing, þó að is more standard and is what you will see most in textbooks and edited texts. Both forms are understood and common; þó að is just a bit more “correct” or formal on the page.