Það er raunhæft að læra smá íslensku á hverjum degi.

Here Það er means it is, not there is.

It is a very common Icelandic pattern with a dummy subject, just like English It is good to rest or It is difficult to understand this. In your sentence, það does not really refer to a concrete thing. It just helps introduce the statement:

Það er raunhæft að... = It is realistic to...

If you said Það er íslenska, that would be different and more literal: That is Icelandic.

Yes. The infinitive phrase að læra smá íslensku á hverjum degi is the idea being judged as realistic.

So the structure is basically:

Það er raunhæft [að læra smá íslensku á hverjum degi].

A more literal version, with the infinitive phrase first, would be:

Að læra smá íslensku á hverjum degi er raunhæft.

That version is grammatical, but the Það er ... að ... pattern is often more natural and common in everyday Icelandic, just as it is in English.

Because the adjective is in the neuter singular form.

The dictionary form is raunhæfur = realistic / feasible. But adjectives change form depending on what they relate to. In this sentence, the thing being described is the whole action að læra smá íslensku á hverjum degi, and Icelandic commonly treats that kind of clause as neuter singular.

So you get:

• raunhæfur — masculine
• raunhæf — feminine
• raunhæft — neuter

That is why the sentence has Það er raunhæft að...

Raunhæft means something like realistic, practical, or feasible.

In this sentence, it suggests that learning a little Icelandic every day is an achievable, sensible goal, not an unrealistic one.

Depending on context, English translations could be:

• realistic
• feasible
• practical

Here realistic is probably the most natural choice.

Here að is the infinitive marker, equivalent to English to in to learn.

So:

• að læra = to learn

This is not the preposition að meaning at / to. Icelandic uses the same word for both functions, so you have to tell from context.

In this sentence, because it comes right before a verb in the infinitive (læra), it means to.

Usually læra means learn, but in some contexts it can overlap with study.

In your sentence, að læra smá íslensku most naturally means:

• to learn a little Icelandic

Depending on context, English speakers might also think of study a little Icelandic, but the core idea is still learning.

A useful comparison:

• læra íslensku = learn Icelandic
• stunda nám or more specific expressions are used when you want to emphasize formal studying

Here smá means a little, a bit of, or some.

So:

smá íslensku = a little Icelandic / some Icelandic

This does not mean small Icelandic. In this kind of sentence, smá works like a quantity word.

It is very common in everyday Icelandic to use smá this way:

• smá kaffi = a little coffee
• smá hjálp = a little help
• smá íslensku = a little Icelandic

Because íslenska is changing case.

The language name is íslenska in the nominative, but læra takes a direct object, and that object is in the accusative case. The accusative form here is íslensku.

So:

• íslenska — nominative
• íslensku — accusative

That is why you get:

að læra smá íslensku

not

að læra smá íslenska

In Icelandic, names of languages are normally not capitalized unless they begin the sentence.

So:

• enska = English
• íslenska = Icelandic
• danska = Danish

This is different from English, which capitalizes language names.

There is also no article here because Icelandic, like English, normally uses language names without an article when talking about the language in general:

• læra íslensku = learn Icelandic

Not:

• learn the Icelandic

Because this is a standard Icelandic time expression meaning every day.

The preposition á is followed here by the dative, which is why both words change form:

• hverjum = dative of hver
• degi = dative of dagur

So:

• á hverjum degi = every day / on every day

Even though English does not use on in every day, Icelandic often uses á in this expression.

Yes. Both are possible, with slightly different style.

• á hverjum degi = every day
• hvern dag = every day
• daglega = daily

So you could also say:

Það er raunhæft að læra smá íslensku hvern dag.
or
Það er raunhæft að læra smá íslensku daglega.

All are understandable. Á hverjum degi sounds very natural and explicit, while daglega is a bit more compact.