Ég þurrka nefið með vasaklútnum þegar ég er með kvef.

With body parts, Icelandic very often uses the definite noun by itself when the owner is obvious from context. Since the subject is ég, nefið naturally means my nose here.

You can add mitt for emphasis or contrast, but it is not the normal default.

Here it is accusative, because it is the direct object of þurrka.

It looks the same as the nominative because nef is a neuter noun, and for many neuter nouns the nominative and accusative singular have the same form. So nefið can be either one, depending on its role in the sentence.

Because með takes the dative case, and the noun is also definite singular.

So:

• vasaklútur = a handkerchief
• vasaklútnum = with the handkerchief

The ending shows both the case and the definite article.

Yes. Með vasaklút means with a handkerchief, in a more indefinite or non-specific sense.

Með vasaklútnum means with the handkerchief, so it sounds more specific or more like a known item.

Not quite.

In með vasaklútnum, með is the ordinary preposition with.

In ég er með kvef, vera með is part of a common idiomatic expression meaning something like to have or to be suffering from. So the two instances of með are related in form, but they are doing different jobs.

Icelandic does have the verb að hafa, but for illnesses and temporary conditions, vera með is very common and natural, especially in everyday speech.

So ég er með kvef is a very normal way to say I have a cold.

Names of illnesses and general conditions are often used without the definite article in Icelandic.

So með kvef is the normal general expression for with a cold / having a cold. You would only expect the article if you were talking about some specific, already identified case.

Yes. You can say:

Þegar ég er með kvef, þurrka ég nefið með vasaklútnum.

Notice that in the main clause, the verb þurrka comes before the subject ég. That happens because Icelandic follows the V2 pattern in main clauses: when something else comes first, the finite verb still stays in the second position.

Not necessarily. Here the present tense is being used for a habitual or general action.

The sentence means that this is what the speaker typically does whenever they have a cold, not only at this exact moment.

Literally, þurrka often means to dry, but in this kind of sentence it is best understood as to wipe.

So Ég þurrka nefið means I wipe my nose. If you specifically want to say I blow my nose, Icelandic would more naturally use ég snýti mér.

• þ is like th in thing
• ð is like th in this

So:

• þurrka begins with the thing sound
• með and nefið contain the this sound

These two letters are very important in Icelandic pronunciation, and English speakers usually benefit from practicing the contrast early.