Die son is warm.

A rough English-friendly pronunciation is dee son is varm.

A few useful notes:

• die is pronounced dee, not like the English verb die
• w in Afrikaans is usually pronounced like an English v
• son has an o sound, so it does not sound like English sun
• r may be tapped or rolled lightly, depending on the speaker

Die is the definite article, so it works like English the.

In this sentence, die son means the sun.

That is just the standard Afrikaans spelling. For English speakers, it can look misleading at first because it resembles the English word die, but in Afrikaans it is normally pronounced dee.

So this is a spelling-and-pronunciation difference you simply get used to.

Afrikaans has mostly lost grammatical gender in its article system.

That means:

• you do not usually need different words for the depending on whether a noun is masculine, feminine, or neuter
• die is the normal definite article for singular nouns
• die is also used for plurals

So die is the expected article here.

This is a classic false friend for English speakers.

In Afrikaans:

• son = sun

In English:

• son = a male child

So although the spelling is the same, the meaning is different.

Yes, very much so. Is is the present-tense form of to be, just like English is.

So:

• Die son is warm follows the same basic pattern as English
• you need is in a normal sentence like this

Leaving it out would sound ungrammatical.

Because it comes after is, where it functions as a predicate adjective.

In Afrikaans, adjectives in that position usually stay in their basic form:

• Die son is warm
• Die water is koud
• Die kos is lekker

So warm stays warm here.

In a simple statement like this, yes. The pattern is very similar:

• Die son = subject
• is = verb
• warm = adjective/complement

So the structure is basically:

• subject + is
  • adjective

That is one reason simple Afrikaans sentences often feel familiar to English speakers.

For a yes/no question, you usually move the verb to the front:

Is die son warm?

That is a very common Afrikaans pattern:

• statement: Die son is warm.
• question: Is die son warm?

Standard Afrikaans usually uses a double nie pattern:

Die son is nie warm nie.

So you will often see:

• one nie earlier in the clause
• another nie at the end

This double negative is normal in Afrikaans grammar.