Learn Hardcore Icelandic: Kvöldgangan í dag verður styttri en í gær. - The evening walk today will be shorter than yesterday.

Kvöldgangan is the evening walk.
The base word is kvöldganga (evening walk), a feminine noun. When you add the definite article (the) in Icelandic, you usually attach it to the end of the noun instead of putting a separate word in front.

So:

kvöldganga = evening walk
kvöldgangan = the evening walk

Here, Kvöldgangan is the subject of the sentence, in the nominative case, definite singular feminine.

What is kvöldganga made from? Why is it one word?

Kvöldganga is a compound noun:

kvöld = evening
ganga = walk, walking

Icelandic very often forms new nouns by putting two nouns together. In English you write evening walk as two words; in Icelandic it becomes one word: kvöldganga. When you make it definite (the evening walk), it becomes kvöldgangan.

Why do we say í dag for “today”? It looks like “in day”.

Yes, í dag literally means in day.
This is just an idiomatic time expression in Icelandic, and it’s the normal way to say today. It’s treated as a fixed phrase.

Grammatically:

í = in
dag = day (accusative singular of dagur)

Similarly, í gær literally means in yesterday, but together they mean yesterday as a time expression.

What exactly is í gær? Is gær a normal noun?

Í gær is the standard way to say yesterday.

Historically, gær is related to an old noun, but in modern Icelandic it only appears in this time expression í gær. You don’t normally use gær on its own the way you use day in English; you just learn í gær as one chunk meaning yesterday.

Again, the structure is:

í = in
gær = yesterday (frozen form used only here)

Why is verður used here? Does it mean “will be”?

Yes. Verður is the 3rd person singular present form of the verb að verða (to become, to get, to turn, and also used as “will be”).

In this sentence:

verður ≈ will be

Icelandic doesn’t have a special future tense form like English does; it usually uses the present tense with future meaning, and að verða is one common way to express will be / will become. So Kvöldgangan í dag verður styttri = “Today’s evening walk will be shorter.”

Could I say mun vera instead of verður?

You could say Kvöldgangan í dag mun vera styttri en í gær, and it is grammatically correct. Mun is another auxiliary often translated as will.

The difference is mainly style and nuance:

verður styttri sounds very natural and slightly more colloquial/neutral.
mun vera styttri can sound a bit more formal or explicit, like you’re stressing the prediction.

In everyday speech, verður styttri is very common.

What does styttri mean and how is it formed?

Styttri is the comparative form of the adjective stuttur (short).

stuttur = short
styttri = shorter
stystur = shortest (superlative)

So in the sentence, styttri means shorter (in comparison to yesterday’s walk). It’s used with en (“than”) to compare two things: styttri en í gær = shorter than yesterday.

Why is the word en used here, and what does it mean?

In this sentence, en means than in a comparison.

So:

styttri en í gær = shorter than yesterday

Be aware that en can also mean but in other contexts, but after a comparative adjective (like styttri, betri, verri, etc.), it usually means than.

Does styttri agree with Kvöldgangan in gender and number?

Yes. The implied structure is Kvöldgangan í dag verður (að vera) styttri, and the adjective styttri agrees with kvöldgangan, which is feminine singular.

Comparative adjectives have their own set of endings, but in the nominative singular feminine, styttri is a correct agreement form. You don’t see gender explicitly marked beyond this shared form, but grammatically the agreement is there: feminine singular subject → feminine singular form of the comparative adjective.

Why is it styttri en í gær and not styttri en kvöldgangan í gær?

You could say the longer version:
Kvöldgangan í dag verður styttri en kvöldgangan í gær.

However, Icelandic (like English) often leaves out repeated words when the meaning is clear. Here, after en (“than”), it’s obvious you’re comparing with the evening walk yesterday, so you can shorten it to just the time phrase: en í gær (“than yesterday”).

English does the same:

Today’s evening walk will be shorter than yesterday’s (walk).
You also omit walk there.

Is the word order Kvöldgangan í dag verður styttri en í gær fixed, or can I move parts around?

Icelandic word order is somewhat flexible, but there are preferred patterns. This sentence is one very natural order:

Kvöldgangan í dag (topic/subject phrase)
verður (verb)
styttri (adjective)
en í gær (comparative phrase)

You can also say:

Í dag verður kvöldgangan styttri en í gær.

This is also natural and emphasizes today a bit more. But you cannot just scramble the words arbitrarily; the verb usually stays in second position in main clauses (V2 rule), counting the first phrase as position 1.

Is Kvöldgangan capitalized because it’s a noun?

No. In Icelandic, nouns are not capitalized by default. Only the first word of a sentence and proper names (people, places, etc.) are capitalized.

Here, Kvöldgangan is capitalized only because it’s the first word of the sentence. If it appeared in the middle of a sentence, it would be written kvöldgangan.

How do you pronounce the tricky parts, especially Kvöldgangan?

Very roughly (using English-like hints):

kv-: like kv in kvetch or kv in some Slavic words; a k plus v together.
ö: a rounded vowel, somewhat like the u in burn (British English) or bird, but with more lip rounding.
ldg sequence in kvöldgangan: Icelandic often simplifies or assimilates clusters like this. The l and d are quite light and close together; the g of ganga begins the next syllable.
ganga: gan-ga, with a hard g both times.

Rhythmically, the stress is always on the first syllable of the word kvöldgangan: KVÖLD-gang-an.