Det är vanligt att vi tar en fika efter jobbet.

Here, det is a dummy subject, just like it in English in sentences such as It is common that... or It is normal to....

It does not refer to a specific thing. It is just there because Swedish usually wants a subject in this kind of sentence structure:

• Det är vanligt att...
• Det är svårt att...
• Det är roligt att...

So det is part of a very common pattern.

Vanligt is the neuter singular form of the adjective vanlig.

In Det är vanligt att..., Swedish uses the neuter form because the adjective is connected to det and to the whole following idea/clause. This is very common after det är:

• Det är viktigt att komma i tid.
• Det är svårt att förstå.
• Det är vanligt att vi tar en fika efter jobbet.

So this is not agreeing with vi. It is part of the fixed pattern det är + adjective + att-clause.

Here, att means that.

Swedish att can do two jobs:

1. Infinitive marker = to

   • att läsa = to read

2. Subordinating conjunction = that

   • Jag tror att han kommer. = I think that he is coming.

In your sentence, att vi tar en fika efter jobbet is a full clause with a subject (vi) and a finite verb (tar), so att means that, not to.

Because this is a subordinate clause.

In Swedish main clauses, the finite verb usually comes in second position (the V2 rule):

• Vi tar en fika efter jobbet.
• Efter jobbet tar vi en fika.

But after a subordinator like att, the word order is different. In a normal subordinate clause, the subject comes before the finite verb:

• att vi tar en fika
• att han kommer i morgon
• att de gillar kaffe

So att vi tar is correct, and att tar vi is not.

Ta en fika is an extremely common Swedish expression.

It means something like:

• have a coffee break
• stop for coffee
• have a fika

But fika is more than just drinking coffee. It often means a social break, usually with coffee, tea, and maybe something sweet like a bun or cake.

So ta en fika is an idiomatic expression. You should learn it as a chunk, not translate each word too literally.

Here, fika is a noun.

In ta en fika, it literally works as the object of tar:

• tar = take/have
• en fika = a fika / a coffee break

But fika can also be a verb:

• Vi fikar efter jobbet. = We have fika after work.

So Swedish uses both:

• ta en fika
• fika

Both are natural.

Because in this expression, fika is treated as a countable event: one fika, one coffee break, one social coffee pause.

That is why Swedish says:

• ta en fika
• ta en paus
• ta en promenad

You usually do not say ta fika here. The article en is part of the normal idiomatic expression.

Because Swedish uses the present tense for habitual actions, just like English often does.

So vi tar en fika efter jobbet can mean:

• we have a fika after work
• we usually have a fika after work

The word vanligt already shows that this is about what is normal or typical, not just one specific moment right now.

Because Swedish normally says efter jobbet for after work.

Literally, jobbet is the definite form, the job / the work, but in this expression it works idiomatically, just like English after work.

So:

• efter jobbet = after work
• på jobbet = at work
• från jobbet = from work

Using just jobb here would sound unnatural.

Yes, you could, but efter jobbet is more natural in everyday spoken Swedish.

The difference is roughly:

• jobbet = everyday, common, conversational
• arbetet = more formal, more neutral, sometimes more abstract

So in ordinary speech, most people would prefer efter jobbet.

Yes, absolutely.

Vi brukar ta en fika efter jobbet is very natural and probably even more common in everyday speech.

The difference in feeling is roughly this:

• Det är vanligt att vi tar en fika efter jobbet.
  This comments on what is usual or typical.

• Vi brukar ta en fika efter jobbet.
  This directly says what we usually do.

So both are correct, but brukar often sounds a bit more direct and conversational.