Learn Hardcore Icelandic: Ég drekk kaffi tvisvar á hverjum degi.

Right now:
- Ég drekk kaffi núna. – I am drinking coffee now.
Habitual actions (things you do regularly):
- Ég drekk kaffi tvisvar á hverjum degi. – I drink coffee twice every day.

Because of tvisvar á hverjum degi (twice every day), this sentence clearly refers to a habit, not necessarily this very moment.

Why is there no word like “a” or “the” before kaffi?

In Icelandic, kaffi is usually treated as a mass noun (like English coffee, water, rice), and very often it appears without an article when speaking in general:

Ég drekk kaffi. – I drink coffee. (in general)
Ég drekk vatn. – I drink water.

If you want to talk about specific coffee, you use the definite form:

Ég drekk kaffið. – I am drinking the coffee.
Ég drekk þetta kaffi. – I drink this coffee.

You normally wouldn’t say something like “a coffee” here in Icelandic; you’d use other constructions (e.g., einn kaffibolla – one cup of coffee).

What case is kaffi in, and why doesn’t it change its form?

Kaffi is a neuter noun, and in the singular its nominative and accusative forms are the same: kaffi.

In Ég drekk kaffi, kaffi is the direct object, so it is in the accusative case. But since nominative = accusative for neuter singular here, it looks unchanged.

Very simplified paradigm:

Nominative singular: kaffi
Accusative singular: kaffi
Dative singular: kaffi
Genitive singular: kaffis

So even though the case changes, the form kaffi stays the same in most everyday uses.

What exactly does tvisvar mean, and how is it different from tveimur sinnum?

Tvisvar is an adverb meaning twice.

Ég drekk kaffi tvisvar á hverjum degi. – I drink coffee twice every day.

You can also say:

tvisvar sinnum – literally twice times
tveimur sinnum – literally two times (using the dative of tveir = two)

In practice:

tvisvar = most common, short, natural:
Ég hef séð hana tvisvar. – I’ve seen her twice.
tvisvar sinnum = a bit more emphatic / explicit but fine.
tveimur sinnum = also okay, slightly more “spelled out”.

In your sentence, tvisvar is the most natural and idiomatic choice.

What does á hverjum degi literally mean, and why that form?

Á hverjum degi literally means “on each day”, and idiomatically “every day”.

á – a preposition that here has the sense of per / on
hverjum – dative singular of hver (each, every), agreeing with degi
degi – dative singular of dagur (day)

The preposition á in this time-expression takes the dative case, which is why you see hverjum degi, not hvern dag.

So the structure is:

á
- dative → á hverjum degi (on each day → every day)

Why is it hverjum degi and not hvern dag?

It comes from preposition + case rules:

Á with a time expression like this typically takes the dative.
The noun dagur (day) in the dative singular is degi.
The adjective/pronoun hver (each, every) must agree in case, number, and gender with the noun it modifies.

So:

Nominative: hver dagur
Accusative: hvern dag
Dative: hverjum degi
Genitive: hvers dags

Because á here requires the dative, you get á hverjum degi, not á hvern dag.

How does dagur decline, and which form is degi?

Dagur is a masculine noun meaning day. Its singular forms (indefinite) are:

Nominative: dagur – (subject) Dagurinn er langur. – The day is long.
Accusative: dag – (direct object) Ég á frí hvern dag. – I have time off every day.
Dative: degi – (indirect object / after certain prepositions)
Á hverjum degi drekk ég kaffi. – On every day I drink coffee.
Genitive: dags – (possession/“of”) í lok dags – at the end of the day.

In á hverjum degi, the form degi is dative singular.

Could I also say Ég drekk kaffi tvisvar á dag? Is there a difference?

Yes, Ég drekk kaffi tvisvar á dag is also used and understood.

Subtle difference in feel:

tvisvar á hverjum degi – literally twice on each day; a bit more explicit/emphatic that this is every single day.
tvisvar á dag – literally twice per day; slightly more compact and general.

In everyday speech, tvisvar á dag is very common. Tvisvar á hverjum degi can sound a touch more formal, careful, or emphatic, but both are correct and natural.

Where can time expressions like tvisvar á hverjum degi go in the sentence? Is the word order fixed?

Icelandic word order is fairly flexible, but there are preferences.

Your sentence:

Ég drekk kaffi tvisvar á hverjum degi.
Subject – verb – object – time

Other natural variants:

Ég drekk tvisvar á hverjum degi kaffi. – possible, but much less natural.
Tvisvar á hverjum degi drekk ég kaffi. – emphasizes the “twice every day” part.

General rule of thumb in neutral statements:

Subject
Verb (finite verb in 2nd position)
Object
Adverbs / time expressions / place, etc.

So your original order is the most typical and natural.

How would the sentence change in the past tense, or with a different subject?

The verb drekka is strong and changes its stem in the past.

Present:

Ég drekk kaffi tvisvar á hverjum degi. – I drink coffee twice every day.

Simple past (habit in the past):

Ég drakk kaffi tvisvar á hverjum degi. – I drank coffee twice every day.

With other subjects in the present:

Þú drekkur kaffi tvisvar á hverjum degi. – You drink coffee twice every day.
Hann/Hún drekkur kaffi tvisvar á hverjum degi. – He/She drinks coffee twice every day.
Við drekkum kaffi tvisvar á hverjum degi. – We drink coffee twice every day.
Þeir/Þær/Þau drekka kaffi tvisvar á hverjum degi. – They drink coffee twice every day.

How do you pronounce Ég drekk kaffi tvisvar á hverjum degi?

Approximate pronunciation (using an English-friendly guide):

Ég – [yeh] or [yei], with a slight [ɣ] sound at the end that may be very weak or almost silent.
drekk – [drekʰ]; the kk is “pre‑aspirated,” like a tiny h before the k.
kaffi – [kʰafːɪ]; ff is long [fː].
tvisvar – roughly [tʰvɪs-var]; tv is like “tv” in “TV,” but said together.
á – [au] (like “ow” in “cow”).
hverjum – [kʰvɛr-jʏm]; initial hv is like kv.
degi – [dɛi-jɪ] or [dei-jɪ].

Spoken together at a natural speed:
Ég drekk kaffi tvisvar á hverjum degi. – [yeh drekʰ kʰafːɪ tʰvɪsvar au kʰvɛrjʏm dei-jɪ].