Það er hálka á gangstéttinni í morgun.

In this kind of sentence, það is a dummy subject. It does not really mean it in a concrete way.

So Það er hálka works a lot like English There is ice / It’s icy.

Icelandic often uses það er to introduce:

• existence
• general conditions
• weather-like statements

So here it is not talking about some specific it.

Hálka means icy slipperiness or slippery icy conditions.

It is not usually the same as just ice as a physical substance. If you say Það er hálka, you are talking about the ground being dangerously slippery because of ice.

A good natural English equivalent is:

• It’s icy
• There are icy conditions
• It’s slippery with ice

Because this sentence is describing a general condition, not a specific previously mentioned thing.

• hálka = icy conditions / slipperiness
• hálkan = the icy patch / the slipperiness

After það er, Icelandic often uses an indefinite noun when introducing a situation or condition. So Það er hálka sounds natural, while Það er hálkan would usually sound wrong or very unusual here.

Because a sidewalk is thought of as a surface, not as something you are inside.

• á = on
• í = in, inside

So:

• á gangstéttinni = on the sidewalk
• í gangstéttinni would suggest being somehow inside the sidewalk, which is not what you want

This is very similar to English: you stand on a sidewalk, not in a sidewalk.

Because á can take different cases depending on meaning:

• dative for location: being on something
• accusative for motion: going onto something

Here there is no movement. The sentence describes where the icy condition is located.

So:

• á gangstéttinni = on the sidewalk
• á gangstéttina = onto the sidewalk

It shows two things at once:

1. definite article: the
2. dative singular ending

So the word breaks down roughly like this:

• gangstétt = sidewalk / pavement
• gangstéttin = the sidewalk
• gangstéttinni = on the sidewalk

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

Because í morgun is an idiomatic time expression.

Even though í often means in, you should learn í morgun as a whole phrase meaning:

• this morning

It refers to the morning of the current day.

This is one of those expressions that is best learned as a set phrase rather than translated word for word.

This is a very important contrast:

• í morgun = this morning
• á morgun = tomorrow

So just changing the preposition completely changes the meaning.

Examples:

• Það var kalt í morgun = It was cold this morning
• Ég fer á morgun = I’m going tomorrow

It is the accusative singular form of morgunn.

The noun morgunn has forms like:

• nominative: morgunn
• accusative: morgun
• dative: morgni

In í morgun, Icelandic uses the accusative in this fixed time expression. For learners, the most useful thing is simply to memorize í morgun as the normal phrase for this morning.

Yes.

You can say:

Í morgun er hálka á gangstéttinni.

That is perfectly natural.

This shows an important Icelandic pattern: the language is generally verb-second. If you put a time phrase first, the finite verb er still comes second.

Notice that when another element comes first, the dummy það is usually dropped in this kind of sentence.

Yes, and it would be natural, but the nuance is slightly different.

• Það er hálka á gangstéttinni focuses on the icy condition existing there
• Gangstéttin er hál focuses on the sidewalk itself being slippery

Both are good Icelandic. The first sounds a bit more like reporting conditions; the second sounds a bit more directly descriptive.

A good beginner guide is:

• þ sounds like th in thin
• ð sounds like th in this, though at the end of a word it can be softer and less strongly pronounced than English speakers expect

So það begins with the unvoiced th sound.

Also, the vowel á in hálka sounds roughly like ow in now.