Jag tar en kundvagn när jag handlar mycket.

Yes, ta literally means take, but in Swedish it is also very commonly used in situations where English would say take, get, or even use.

So Jag tar en kundvagn is a very natural way to say I take/get a shopping cart.

It suggests that you pick one up for your use in the store. English often does the same thing with take a cart.

Kundvagn means shopping cart or trolley.

It is a compound noun:

• kund = customer
• vagn = wagon, cart, trolley

So the literal idea is something like customer cart.

Because kundvagn is an en-word in Swedish.

Swedish nouns have grammatical gender, and for common gender nouns you use en:

• en kundvagn
• kundvagnen = the shopping cart

This is something you mostly just have to learn together with the noun.

En kundvagn means a shopping cart, while kundvagnen means the shopping cart.

In this sentence, the speaker is talking generally, not about one specific cart. So the indefinite form is the natural choice:

• Jag tar en kundvagn = I take a shopping cart
• Jag tar kundvagnen = I take the shopping cart

The second version would sound like a specific cart is already known from the context.

Here, handlar means shop or do shopping.

The verb is handla, and it has a few meanings depending on context:

• handla = to shop / buy groceries / buy things
• handla om = to be about

In this sentence, it clearly means to shop:

• när jag handlar mycket = when I shop a lot / when I’m buying a lot

Because handla can be used on its own to mean go shopping or do shopping.

So Swedish can say:

• Jag handlar. = I’m shopping.
• Jag handlar mycket. = I shop a lot / I’m buying a lot.

You do not need to add what you are buying unless you want to be more specific.

Mycket here means a lot and modifies the verb handlar.

So:

• jag handlar mycket = I shop a lot / I buy a lot

This is different from många, which is used with countable nouns:

• många varor = many items
• mycket mat = a lot of food
• handlar mycket = shop a lot

So mycket is correct because it is describing the amount or extent of the shopping, not a plural noun.

När literally means when, but in sentences like this it often has the sense of when/whenever.

So:

• Jag tar en kundvagn när jag handlar mycket.

means something like:

• I take a shopping cart when(ever) I’m buying a lot.

In English, if might also sound natural in some contexts:

• I take a shopping cart if I’m buying a lot.

But Swedish naturally uses när here for a repeated, typical situation.

Because när jag handlar mycket is a subordinate clause, and Swedish subordinate clauses normally keep the basic subject + verb order:

• när jag handlar mycket

not

• när handlar jag mycket

The second version would sound like a direct question: When do I shop a lot?

This is a very important difference in Swedish:

• Main clauses often follow the verb-second rule
• Subordinate clauses do not use that pattern in the same way

Because Swedish often uses the present tense for habitual actions or general truths, just like English does.

So:

• Jag tar en kundvagn när jag handlar mycket.

means a general habit:

• I take a shopping cart when I shop a lot.

It is not just about what the speaker is doing right now. It describes what they usually do in that situation.

Yes, you could, but it means something slightly different.

• Jag tar en kundvagn = I take/get a shopping cart
• Jag använder en kundvagn = I use a shopping cart

Tar focuses on the action of taking one. Använder focuses on the fact that you use one.

In this kind of everyday sentence, tar en kundvagn sounds very natural.

Not exactly.

• Jag handlar mycket usually means I shop a lot or I buy a lot
• Jag handlar ofta means I shop often

So:

• mycket = a lot, in large quantity
• ofta = often, frequently

In this sentence, the idea is that the person needs a shopping cart when the amount of shopping is large, not necessarily when the shopping happens frequently.