Ég nota blandarann til að mauka súpuna.

Yes. Að nota is the infinitive, but nota is also the 1st person singular present tense form: ég nota = I use.

That is very common with Icelandic verbs ending in -a.

For example:

• að nota = to use
• ég nota = I use
• þú notar = you use
• hann/hún notar = he/she uses

So in this sentence, nota is a finite verb, not an infinitive.

Blandari is the basic dictionary form, meaning blender.

In the sentence, the blender is the direct object of nota, so the noun has to be in the accusative case. It is also definite: the blender, not just a blender.

That gives:

• blandari = blender
• blandarinn = the blender, as subject
• blandarann = the blender, as object

So Ég nota blandarann means I use the blender.

Because súpa is a feminine noun, and here it is:

1. definite = the soup
2. the direct object of mauka

So it appears in the accusative singular definite form:

• súpa = soup
• súpan = the soup, as subject
• súpuna = the soup, as object

That is why the sentence has súpuna.

In Icelandic, the definite article is usually attached to the end of the noun instead of being a separate word.

So:

• blandari = blender
• blandarinn / blandarann = the blender
• súpa = soup
• súpan / súpuna = the soup

English uses a separate word, but Icelandic usually uses an ending.

Til að means to in the sense of in order to or for the purpose of.

So:

• Ég nota blandarann til að mauka súpuna
  = I use the blender in order to purée the soup

It introduces a purpose phrase: what the blender is being used for.

Because til að + infinitive is the normal pattern for expressing purpose.

So:

• til að mauka = to purée / in order to purée

You should learn til að as a unit when it introduces an infinitive.

Because both are direct objects:

• blandarann is the object of nota
• súpuna is the object of mauka

Even though mauka is in an infinitive phrase, it can still take its own object, and that object still gets the case the verb requires.

So the structure is:

• Ég nota [blandarann]
• til að mauka [súpuna]

Mauka means something like to mash, to purée, or to blend into a smooth mixture.

It is often used for food. In this sentence, it suggests making the soup smoother, often with a blender or hand blender.

So it is not just mix in a general sense; it has more of a turning into a purée or soft mass sense.

Yes, but the meaning changes.

• Ég nota blandarann til að mauka súpuna
  = I use the blender to purée the soup

• Ég nota blandara til að mauka súpu
  = I use a blender to purée soup

The second version is more general and less specific. It also shows that even without the definite article, the nouns still change for case:

• blandara is accusative of blandari
• súpu is accusative of súpa

The word order here is the most neutral and natural one:

• Ég = subject
• nota = verb
• blandarann = object
• til að mauka súpuna = purpose phrase

So the sentence follows a normal subject–verb–object pattern, with the purpose phrase after it.

You can move things around for emphasis, for example:

• Til að mauka súpuna nota ég blandarann.

That is still correct, but it is less neutral and puts extra focus on the purpose.

Often not. In natural speech, að is usually unstressed and reduced.

The ð in að is often very weak, and in fast speech the whole word can sound quite short. So learners may not always hear a strong separate consonant there.

In careful speech, you may hear it more clearly, but in everyday speech it often sounds lighter than English speakers expect.