Við förum inn á kaffihúsið því það er kalt úti.

In Icelandic, the present tense often covers what English expresses as either present or near future.

So Við förum inn á kaffihúsið can mean:

• We go into the café
• We’re going into the café
• We’ll go into the café

The exact English translation depends on context. In this sentence, it most naturally sounds like an immediate decision or a planned next action because it’s cold outside.

Because fara is not fully regular.

Its present-tense forms are:

• ég fer
• þú ferð
• hann / hún / það fer
• við förum
• þið farið
• þeir / þær / þau fara

So förum is simply the correct we form of fara in the present tense. The vowel change from a to ö is part of the verb’s normal pattern and just has to be learned.

Inn means in / inside, and it emphasizes movement inward.

Á is the preposition used with kaffihús in this expression.

So:

• fara á kaffihús = go to a café
• fara inn á kaffihús = go into a café

The word inn makes it clear that the movement is from outside to inside, not just toward the place in a general sense.

Because Icelandic does not always use the same preposition that English uses.

Even though English says in/into the café, Icelandic commonly uses á with places like this. This is something learners often just have to get used to: certain nouns go with certain prepositions idiomatically.

So the natural expression is:

• á kaffihús
• inn á kaffihús

not usually í kaffihús.

The ending -ið is the definite article attached to the noun.

So:

• kaffihús = a café / café
• kaffihúsið = the café

Icelandic usually adds the to the end of the noun instead of using a separate word.

Here, kaffihúsið is also in the form used after motion with á. Since kaffihús is a neuter noun, the definite singular form here is kaffihúsið.

Because á changes case depending on whether there is movement or location.

With movement toward/into a place, á takes the accusative:

• inn á kaffihúsið

With location at/in a place, á takes the dative:

• á kaffihúsinu = at/in the café
• inni á kaffihúsinu = inside the café

So:

• við förum inn á kaffihúsið = we go into the café
• við erum á kaffihúsinu = we are at/in the café

Here því means because.

So:

• ..., því það er kalt úti = ..., because it is cold outside

This is a common and natural way to give a reason. A fuller alternative is af því að, which also means because:

• Við förum inn á kaffihúsið af því að það er kalt úti.

Both are correct.

That það works like English it in expressions such as it is cold.

It does not refer to a specific thing. It is just the normal subject used in weather and general-condition statements.

So:

• það er kalt = it is cold

This is very similar to English.

Because adjectives in Icelandic agree with the subject, and here the subject is það, which is neuter singular.

The adjective kaldur has these basic forms:

• kaldur = masculine
• köld = feminine
• kalt = neuter

So:

• hann er kaldur = he is cold
• hún er köld = she is cold
• það er kalt = it is cold

That is why kalt is used here.

Úti means outside / outdoors.

In það er kalt úti, it tells you where it is cold:

• it is cold outside

Putting úti at the end is very natural and neutral. Icelandic often places this kind of adverb after the main adjective or later in the clause.

Yes. This is very normal Icelandic word order.

The structure is:

• Við förum inn á kaffihúsið = main clause
• því það er kalt úti = reason clause

A learner can think of it as:

• We are going into the café, because it is cold outside.

Nothing unusual is happening here; it is a good example of everyday Icelandic sentence structure.