Ég elska alla.

Because elska is the 1st person singular present form: ég elska = I love.

It just happens to look the same as the infinitive að elska = to love.

A quick mini-pattern:

• að elska – to love
• ég elska – I love
• þú elskar – you love
• hann / hún / það elskar – he / she / it loves
• við elskum – we love
• þið elskið – you love
• þeir / þær / þau elska – they love

So in Ég elska alla, elska is not the infinitive here; it is the correctly conjugated verb for ég.

Because alla is the accusative form, and elska takes a direct object in the accusative case.

Here, alla is the object — the people being loved — so accusative is required.

Compare:

• Allir elska mig. – Everyone loves me.
  
  • allir = nominative, because it is the subject
• Ég elska alla. – I love everyone.
  
  • alla = accusative, because it is the object

So allir and alla are different forms of the same word, used for different jobs in the sentence.

Here alla is being used on its own, like a pronoun, and means everyone or all of them.

It comes from allur, which means all.

In this sentence, it normally refers to people, not things. Also, Icelandic often uses the masculine plural form as the default for a mixed group or when gender is not specified.

Useful contrasts:

• Ég elska alla. – I love everyone / I love them all
• Ég elska allar. – I love all of them (if they are all female)
• Ég elska allt. – I love everything

Yes.

Without any special context, the most natural meaning is I love everyone.

But if the conversation is already about a specific group, it can also mean I love them all.

So the exact English translation depends on context:

• general statement: I love everyone
• known group: I love them all

Because this sentence uses a finite verb (I love), not an infinitive (to love).

• að elska = to love
• ég elska = I love

So:

• Ég elska alla. – I love everyone.
• Að elska alla er erfitt. – To love everyone is difficult.

You only use að when you need the infinitive form.

A rough English-friendly guide is:

• Ég – roughly yeg, with a long ye sound
• elska – roughly EL-ska
• alla – roughly aht-la

So the whole sentence is approximately:

yeg EL-ska aht-la

A few useful notes:

• Stress in Icelandic is usually on the first syllable.
• The g in Ég is softer than an English g, and in everyday speech it may sound weak.
• The ll in alla does not sound like ordinary English ll.

If pronunciation matters to you, it is very worth listening to native audio, because Icelandic sounds can be hard to guess from spelling alone.

No.

In Icelandic, ég is not always capitalized. It is only capitalized when normal spelling rules require it, such as at the beginning of a sentence.

So:

• Ég elska alla.
• Hann veit að ég elska alla.

One important detail: the accent stays. It is ég, not eg.

Yes. This is the neutral, standard order:

subject + verb + object

• Ég – subject
• elska – verb
• alla – object

Icelandic can change word order for emphasis. For example:

• Alla elska ég.

That is possible, but it sounds more emphatic or marked, something like:

• Everyone, I love
• It’s everyone that I love

For a simple, ordinary statement, Ég elska alla is the natural choice.

No.

Like English love, elska can be used in different ways depending on context:

• romantic love
• family affection
• deep emotional warmth
• very strong liking

So Ég elska alla does not have to sound romantic. It could sound:

• sincere
• idealistic
• spiritual
• exaggerated
• humorous

If you want a milder idea like like, Icelandic often uses líka við instead of elska.

• Ég is nominative, because it is the subject.
• alla is accusative, because it is the direct object of elska.

This is a very common Icelandic pattern:

• subject → nominative
• direct object → often accusative

A big part of learning Icelandic is learning which case a verb requires. Elska is one of the common verbs that takes an accusative object.