Ég er vanur að elda kjúkling með pasta á virkum dögum.

Að vera vanur að + infinitive means to be used to / accustomed to doing something.

In this sentence, it describes a current habit or something the speaker is comfortable/accustomed to doing. That is slightly different from English used to, which often refers to a past habit that may no longer be true.

So this Icelandic structure can mean something like:

• I am used to cooking...
• I’m in the habit of cooking...

Depending on context, English may also translate it more naturally as I usually cook..., but the Icelandic wording emphasizes habit/accustomedness.

Vanur agrees with the subject in gender, number, and case.

Here the subject is ég, and the adjective is in the form used for a masculine singular speaker:

• Ég er vanur að... = said by a man
• Ég er vön að... = said by a woman

So if a female speaker says the same sentence, it would normally be:

• Ég er vön að elda kjúkling með pasta á virkum dögum.

This is a very common thing learners notice in Icelandic: adjectives often reflect the speaker’s gender.

Because að is the infinitive marker here, like English to in to cook.

After vanur, Icelandic normally uses:

• vanur að gera eitthvað = used to doing something

So:

• að elda = to cook

You should think of vanur að as a very common pattern.

Because kjúklingur is the nominative form, but here the word is the direct object of elda, so it goes into the accusative.

• nominative: kjúklingur
• accusative: kjúkling

So:

• Ég elda kjúkling. = I cook chicken.

This is a standard Icelandic case pattern: many transitive verbs, including elda, take a direct object in the accusative.

Here með means with, and in this meaning it normally takes the dative.

So the phrase is:

• með pasta = with pasta

A detail that can confuse learners: pasta does not visibly change here, so you do not immediately see the dative ending. But the preposition is still governing the dative.

Compare with a word where the form changes more clearly:

• með sósu = with sauce
  from sósa

So the grammar is the same, even if pasta looks unchanged.

Because á here is part of a time expression meaning on weekdays, and the phrase is in the dative plural.

Base forms:

• virkur = active, working
• dagur = day

In the sentence:

• virkum = dative plural of virkur
• dögum = dative plural of dagur

So:

• á virkum dögum = on weekdays / on working days

Both the adjective and the noun have to match in case and number.

Both, in a way.

Literally, virkur dagur is something like a working/active day, but in normal usage á virkum dögum is commonly understood as:

• on weekdays
• on working days
  as opposed to weekends

So in most everyday contexts, on weekdays is the most natural English understanding.

It is natural, but it has a particular nuance.

• Ég er vanur að... emphasizes habit or being accustomed to
• Ég elda venjulega... or Ég elda oft... emphasizes usual frequency

So these are slightly different in tone:

• Ég er vanur að elda kjúkling með pasta á virkum dögum.
  = I’m used to / I’m in the habit of cooking chicken with pasta on weekdays.

• Ég elda venjulega kjúkling með pasta á virkum dögum.
  = I usually cook chicken with pasta on weekdays.

• Ég elda oft kjúkling með pasta á virkum dögum.
  = I often cook chicken with pasta on weekdays.

So the original sentence is good, but it is not just a plain frequency statement.

Yes. Icelandic word order is fairly flexible, especially when you move time expressions for emphasis.

The original order is completely normal:

• Ég er vanur að elda kjúkling með pasta á virkum dögum.

But you could also say:

• Á virkum dögum er ég vanur að elda kjúkling með pasta.

That puts more focus on á virkum dögum.

What you generally want to keep together is the structure:

• er vanur að elda

because that is the core verbal idea.

Usually it means chicken with pasta in a general sense, often understood as chicken served with pasta.

The preposition með is broad. It can mean:

• together with
• accompanied by
• with as part of the meal

So the phrase does not necessarily mean the chicken is physically mixed into the pasta.

If you wanted to make the relationship clearer, you could choose other wording depending on the exact meaning.

No. In this structure, að is normally required.

You need:

• vera vanur að + infinitive

So the correct pattern is:

• Ég er vanur að elda...

Without að, it sounds ungrammatical in standard Icelandic.