Barnen ritar med kritor, och deras mamma ritar också en teckning.

Barn means children in general, while barnen means the children.

The ending -en is the definite plural ending here, so:

• ett barn = a child
• barn = children
• barnen = the children

In this sentence, it refers to specific children, so Swedish uses barnen.

In Swedish, the is usually attached to the noun as an ending, instead of being a separate word like in English.

For example:

• barnen = the children
• mamman = the mother

But in this sentence we have deras mamma, not mamman, because possession works differently. When a noun has a possessor like their, it normally does not take the definite ending.

So:

• barnen = the children
• deras mamma = their mother
  not deras mamman

This is a very common learner question.

Swedish uses sin/sitt/sina for a reflexive possessor, meaning the possessor is the subject of the same clause.

Here, the subject is barnen in the first part, but deras mamma means their mother — the mother belongs to the children. Since the possessor is barnen, not the mother herself, deras is correct.

Compare:

• Barnen ritar med kritor, och deras mamma ritar också.
  = The children are drawing with crayons, and their mother is drawing too.

But:

• Mamman ritar sin teckning.
  = The mother is drawing her own drawing.

So in your sentence, deras is used because it means the children’s mother.

Med kritor means with crayons.

Swedish often leaves out the article in plural nouns when speaking generally about tools, materials, or things used in an activity.

So:

• med kritor = with crayons
• med pennor = with pens
• med händerna = with the hands (this one is definite for a different reason)

You do not need something like några kritor unless you specifically want to say some crayons.

Kritor is the plural of krita, which means crayon or sometimes chalk, depending on context.

Forms:

• en krita = a crayon
• kritan = the crayon
• kritor = crayons
• kritorna = the crayons

So med kritor literally means with crayons.

Också means also/too, and its position in Swedish often differs from English.

In this sentence:

• deras mamma ritar också en teckning

the adverb också comes after the verb ritar and before the object en teckning.

This is a very natural placement in Swedish. English often puts also in a similar place:

• Their mother is also drawing a picture

or uses too later:

• Their mother is drawing a picture too

So the Swedish word order is normal here.

En teckning means a drawing or a picture.

The word en is the indefinite article, like a/an in English.

Forms:

• en teckning = a drawing
• teckningen = the drawing

So the sentence says that the mother is drawing a drawing, not a specific previously mentioned drawing.

No — Swedish verbs do not change according to the subject the way English verbs sometimes do.

So:

• jag ritar = I draw / am drawing
• du ritar = you draw / are drawing
• barnen ritar = the children draw / are drawing
• mamman ritar = the mother draws / is drawing

The verb form stays the same.

It can mean either, depending on context.

Swedish present tense often covers both:

• draw / draws
• am drawing / is drawing / are drawing

So:

• Barnen ritar can mean The children draw or The children are drawing
• In this sentence, the natural meaning is probably The children are drawing

If Swedish wants to be more explicit about an ongoing action, it can sometimes use other expressions, but the simple present is very common.

The comma is optional here and depends somewhat on style.

The sentence contains two coordinated clauses:

• Barnen ritar med kritor
• och deras mamma ritar också en teckning

A comma before och can be used to make the sentence easier to read, especially when the clauses are a bit longer. In many cases, Swedish also allows no comma here.

So both of these can be acceptable:

• Barnen ritar med kritor, och deras mamma ritar också en teckning.
• Barnen ritar med kritor och deras mamma ritar också en teckning.

Yes, absolutely.

You can say:

• Barnen ritar med kritor, och deras mamma ritar också.

That means The children are drawing with crayons, and their mother is drawing too.

Adding en teckning makes the action more explicit, but it can sound slightly repetitive to English speakers because draw a drawing is less common in English. In Swedish, rita en teckning is possible and understandable, though often just rita is enough if the context is clear.