Het varken is groot.

Because varken is a het-word in Dutch. Dutch nouns take one of two definite articles:

• de for common-gender nouns
• het for neuter nouns

Varken is neuter, so the correct article is het.

A useful thing to remember:

• singular: het varken
• plural: de varkens

So even het-words take de in the plural.

Varken means pig.

It is a singular noun here:

• het varken = the pig

The plural is:

• varkens = pigs
• de varkens = the pigs

This is the normal Dutch word order for a simple main clause:

subject + verb + complement

So:

• Het varken = subject
• is = verb
• groot = adjective/complement

This is very similar to English:

• The pig is big

Dutch main clauses usually put the finite verb in the second position, which is exactly what happens here.

Yes. Is is the third-person singular form of zijn, which means to be.

So:

• ik ben = I am
• jij bent = you are
• hij/zij/het is = he/she/it is

In Het varken is groot, is works just like English is in The pig is big.

Because groot is being used after the verb is. In that position, Dutch adjectives usually do not take -e.

Compare:

• Het varken is groot. = The pig is big.

  • adjective used predicatively → groot

• Het grote varken = the big pig

  • adjective used before the noun → usually grote

So the short version is:

• after a verb like is → usually no -e
• before a noun → often -e

You would say:

• een groot varken

Here is the contrast:

• het varken is groot = the pig is big
• het grote varken = the big pig
• een groot varken = a big pig

Notice something interesting:

• with het grote varken, the adjective gets -e
• with een groot varken, it stays groot

That is because varken is a het-word, and after een with a singular neuter noun, the adjective usually has no -e.

A rough guide for English speakers:

• het ≈ hut or a very reduced ut in everyday speech
• varken ≈ VAR-ken
  
  • the v in Dutch is often softer than in English, sometimes close to f depending on accent
  • the r varies by region
• is ≈ iss
• groot ≈ a guttural khroht
  
  • the g is the famous Dutch throaty sound
  • oo is like a long o
  • t is clearly pronounced

Very roughly: hut VAR-ken iss khroht

Usually het varken means the pig, referring to a specific pig.

But Dutch, like English, can sometimes use the singular with the definite article in a more general sense, depending on context. For example, it can sometimes mean something like the pig as an animal/species.

Still, in a simple sentence like Het varken is groot, most learners should understand it first as:

• The pig is big

Here, groot is an adjective.

More specifically, it is a predicate adjective because it comes after the verb is and describes the subject:

• Het varken = the thing being described
• groot = the description

So groot tells us a quality of the pig: it is big.

It can exist, but it is not the normal neutral word order.

The standard, neutral sentence is:

• Het varken is groot.

If you move groot to the front:

• Groot is het varken.

that sounds more literary, emphatic, or unusual. It puts strong focus on groot. A beginner should stick with Het varken is groot unless there is a special reason to change the emphasis.

You would usually say:

• Het varken is niet groot. = The pig is not big.

Use niet to negate the adjective phrase here.

So:

• is groot = is big
• is niet groot = is not big

In Dutch yes/no questions, the verb usually comes first:

• Is het varken groot? = Is the pig big?

That is very similar to English inversion:

• The pig is big.
• Is the pig big?

So the pattern is:

• statement: Het varken is groot.
• question: Is het varken groot?