Kaffen er for kald nå.

Kaffe is the basic form of the noun coffee (indefinite: coffee in general).
Kaffen is the definite form: the coffee (a specific coffee you and the listener know about).

• Kaffe er godt. = Coffee is good. (coffee in general)
• Kaffen er for kald nå. = The coffee is too cold now. (the particular coffee in front of you)

Norwegian usually marks definite nouns with an ending (here -en) instead of a separate word like the.

In Bokmål, kaffe is normally masculine.

You can tell by looking it up in a dictionary: it will usually show (en) kaffe.
That means:

• Singular indefinite: en kaffe
• Singular definite: kaffen

There is no reliable rule to guess gender for all nouns, so learners generally need to memorize it or check a dictionary.

Here for is not the preposition for (as in for you). It is an adverb meaning too (excessively).

• for kald = too cold
• for stor = too big
• for dyr = too expensive

Compare:

• Kaffen er veldig kald. = The coffee is very cold. (strong, but not necessarily a problem)
• Kaffen er for kald. = The coffee is too cold. (this is a problem / not acceptable)

The adjective agrees with the gender of the noun it describes:

• kaffe is masculine → kald
• vann (water) is neuter → kaldt

So:

• Kaffen er (for) kald. = The coffee is (too) cold.
• Vannet er (for) kaldt. = The water is (too) cold.

You use kaldt either with a neuter noun or in an impersonal sentence like Det er for kaldt (It is too cold).

Yes. Both are correct:

• Kaffen er for kald nå.
• Nå er kaffen for kald.

Norwegian main clauses follow the verb-second rule:

• If the subject (kaffen) comes first, the verb (er) is second.
• If something else (like nå) comes first, the verb is still second, and the subject comes after the verb.

The difference is mainly one of emphasis:

• Kaffen er for kald nå. → neutral, little extra emphasis.
• Nå er kaffen for kald. → puts a bit more focus on now (it has reached that point now).

The most natural places:

1. At the end: Kaffen er for kald nå.
2. At the beginning: Nå er kaffen for kald.

Nå in the very middle, like Kaffen nå er for kald, is not natural standard Norwegian.

Yes:

• Kaffen er kald nå. = The coffee is cold now. (a neutral description)
• Kaffen er for kald nå. = The coffee is too cold now. (it is colder than you want; there is a problem)

Adding for introduces the idea of too much / not acceptable.

Approximate pronunciation (standard Eastern Norwegian):

• kaffen → [ˈkɑfːən]

  • kaff- like kaf in cafe, but with a short a
  • double f → longer f sound
  • -en like a weak en

• kald → [kɑld]

  • a like a in father, but shorter
  • ld is pronounced fully [ld]

• nå → [noː]

  • long o sound, like in nor but without the r
  • the å letter is usually pronounced like a long o in English more (without the r)

Regional accents vary, but these are good target sounds.

Yes, for kald is inherently negative or at least problematic:

• for kald = too cold (colder than desired / acceptable)

So Kaffen er for kald nå almost always implies you are not happy with the temperature.
If you just want to describe it neutrally, use kald or veldig kald instead.

Yes, but the meaning changes slightly:

• Kaffen er veldig kald nå. = The coffee is very cold now. (strong coldness, but not automatically a complaint)
• Kaffen er for kald nå. = The coffee is too cold now. (problem; not suitable to drink the way you want)

So veldig is about degree, while for is about exceeding a limit.

You simply switch the adjective:

• Kaffen er for varm nå. = The coffee is too hot now.

Adjective pairs:

• kald = cold
• varm = warm / hot

Change the verb er (is) to var (was):

• Kaffen var for kald. = The coffee was too cold.
• Kaffen var for kald i stad. = The coffee was too cold a moment ago.

Verb å være (to be) in the most common forms:

• er = is / am / are (present)
• var = was / were (past)
• har vært = has/have been (present perfect)

In Norwegian, the normal way to say the coffee is just:

• kaffen (with the definite ending)

You only add den when you want a stronger, more specific reference, similar to that coffee or this coffee in English:

• Den kaffen er for kald nå.
  → That (particular) coffee is too cold now.

In a neutral sentence about the coffee on the table, Kaffen er for kald nå is the natural choice.