Ég borða mat.

Because mat is the accusative form, and matur is the nominative form.

In this sentence, mat is the direct object of borða (to eat), so Icelandic uses the accusative:

• matur = nominative, used for the subject
• mat = accusative, used for the object

So:

• Matur er góður. = Food is good.
  Here food is the subject, so it is matur.
• Ég borða mat. = I eat food.
  Here food is the object, so it is mat.

Here, borða is the present tense, specifically first person singular: I eat.

With borða (to eat), the present tense goes like this:

• ég borða = I eat
• þú borðar = you eat
• hann/hún/það borðar = he/she/it eats
• við borðum = we eat
• þið borðið = you all eat
• þeir/þær/þau borða = they eat

So in Ég borða mat, the verb agrees with ég.

This is the normal Icelandic word order for a basic statement:

subject + verb + object

So:

• Ég = subject
• borða = verb
• mat = object

That is very similar to English I eat food.

Icelandic can change word order for emphasis or in certain sentence types, but this sentence uses the most neutral, standard order.

Normally, yes, you should include ég.

Unlike some languages such as Spanish or Italian, Icelandic usually keeps the subject pronoun in ordinary sentences:

• Ég borða. = I eat.

If you just say Borða, that usually does not work as a complete normal statement meaning I eat.

So Icelandic generally wants the pronoun stated.

Because Icelandic often leaves the noun bare when speaking generally.

So Ég borða mat naturally means something like:

• I eat food
• I am eating food
• sometimes even I eat some food, depending on context

Icelandic does not always need an indefinite article like English a/an, because Icelandic has no true indefinite article.

If you want the food, Icelandic usually adds the definite article to the end of the noun:

• maturinn = the food (nominative)
• matinn = the food (accusative)

So:

• Ég borða mat. = I eat food.
• Ég borða matinn. = I eat the food.

The accent mark in é is part of the spelling and shows that it is a different vowel from plain e.

So é is not just e with decoration. It is its own vowel sound in Icelandic.

In ég, the word is pronounced roughly like yeg or yegh for an English speaker, though not exactly.

So yes, the accent matters and should be written.

The letter ð is often pronounced somewhat like the th in this, though the exact Icelandic sound can vary by position.

In borða, English speakers can usually get close with something like:

BOR-tha or BOR-dha

That is only an approximation, but it is a useful starting point.

A few helpful points:

• ð is a real Icelandic letter
• it is different from d
• it often sounds soft, not like a strong English d

Yes. Borða is both:

• the infinitive = to eat
• the 1st person singular present = I eat
• also the 3rd person plural present = they eat

This is very common in Icelandic: the same form can have more than one job, and the sentence tells you which one it is.

For example:

• að borða = to eat
• ég borða = I eat
• þeir borða = they eat

The að usually helps show that it is the infinitive.

Yes, depending on context.

The simple present in Icelandic can often cover both:

• I eat
• I am eating

So Ég borða mat can be understood in either a general or current sense, depending on the situation.

If you want to make the ongoing action clearer, Icelandic often uses:

• Ég er að borða mat. = I am eating food.

That structure is very common for an action happening right now.

You add ekki (not):

• Ég borða ekki mat. = I do not eat food.

Notice that Icelandic does not use a helping verb like English do here.

English:

• I do not eat

Icelandic:

• Ég borða ekki

So the main verb stays as it is, and ekki is added.

Sometimes, yes, but it changes the feel.

The neutral version is:

• Ég borða mat.

You might also see something like:

• Mat borða ég.

That is more marked and sounds like Food, I eat or It is food that I eat, depending on context. It gives emphasis or contrast.

So for a beginner, the safest pattern is:

subject + verb + object

Because the ég form of many Icelandic present-tense verbs does not take -r.

Compare:

• ég borða = I eat
• þú borðar = you eat
• hann borðar = he eats

So the -r appears in some other present-tense forms, but not in the first person singular here.

This is a useful pattern to notice in Icelandic verbs.

It is singular.

The noun here refers to food as a mass noun, much like English food. Even though food is not usually counted item by item in this sentence, the grammar is still singular.

So:

• mat = singular accusative of matur

If you were talking about different dishes or meals in another context, Icelandic might use different forms, but in this sentence mat is singular.