V obchodě si vezmi košík, protože tvoje taška je už plná.

Because v means in here, and after v you usually use the locative case when talking about location.

• obchod = shop/store
• v obchodě = in the shop/in the store

So:

• Jsem v obchodě. = I am in the store.

If you were talking about motion to the store, you would use a different form:

• Jdu do obchodu. = I’m going to the store.

So the contrast is:

• v obchodě = in the store, located there
• do obchodu = to the store, movement toward it

Si is a very common Czech clitic pronoun. In this sentence, it suggests doing something for yourself or for your own use.

So vezmi si košík is more natural than just vezmi košík in many everyday situations. It feels like:

• take yourself a basket
• pick up a basket for yourself

English usually does not translate si directly, but Czech often uses it where English does not.

Compare:

• Vezmi košík. = Take a basket.
• Vezmi si košík. = Take a basket / Pick up a basket for yourself.

The version with si is very idiomatic in Czech.

Vezmi is the imperative form, used for giving a command or instruction to one person.

The verb is vzít = to take.

Its imperative forms are irregular:

• vezmi = take! (to one person)
• vezměte = take! (to more than one person, or formal you)

So:

• Vezmi si košík. = Take a basket. (singular/informal)
• Vezměte si košík. = Take a basket. (plural or formal)

vezmeš means you will take / you take, not a command.

This is about aspect, which is very important in Czech verbs.

• vzít / vezmi = perfective
• brát / ber = imperfective

In a command like this, Czech often prefers the perfective when you mean a single complete action:

• Vezmi si košík. = Take a basket. / Pick up a basket.

That sounds natural because it means: perform this one action.

Ber si košík is possible in some contexts, but it sounds different, often more like an ongoing, repeated, or less bounded action. In a store instruction, vezmi si košík is the normal choice.

It is in the accusative, because it is the direct object of vezmi si.

But košík is a masculine inanimate noun, and for many masculine inanimate nouns, the accusative singular looks the same as the nominative singular.

So:

• nominative: košík
• accusative: košík

That is why there is no visible change here.

Compare with a masculine animate noun, where you often do see a change:

• student → vidím studenta

But:

• košík → vezmi košík

Both are possible.

• tvoje is the more common everyday form
• tvá is shorter and can sound a bit more literary, formal, or emphatic depending on context

So:

• tvoje taška
• tvá taška

both mean your bag.

In normal spoken Czech, tvoje taška is very natural.

The same kind of variation exists with other possessives:

• moje / má
• tvoje / tvá
• svoje / svá

Learners will usually hear the longer forms very often in conversation.

Taška is a feminine noun, and that affects the forms of words that agree with it.

That is why you get:

• tvoje taška — possessive agrees with a feminine singular noun
• plná — adjective also agrees with a feminine singular noun

If the noun were masculine or neuter, the adjective would change:

• batoh je plný = the backpack is full
• auto je plné = the car is full

So plná is feminine singular to match taška.

Because plná is an adjective, and it must agree with taška, which is feminine singular.

• taška je plná = the bag is full

Plno is a different word. It is often used more like an adverb or predicative expression meaning full / crowded / a lot, for example:

• Je tu plno. = It’s full/crowded here.
• Mám plno práce. = I have a lot of work.

So in this sentence, because we are describing a specific noun (taška), Czech uses the agreeing adjective plná.

Už means already.

It shows that the bag is full already / by now, which explains why you should take a basket.

In Czech, word order is flexible, so už can move around somewhat depending on emphasis. Here:

• tvoje taška je už plná

is completely natural.

You may also hear:

• tvoje taška už je plná

Both are possible. The difference is mostly about rhythm and emphasis, not basic meaning.

Because protože means because and introduces a subordinate clause.

In standard Czech spelling, subordinate clauses are separated by commas.

So:

• V obchodě si vezmi košík, protože tvoje taška je už plná.

The part after protože explains the reason.

This is similar to English, although English comma usage with because is less fixed than Czech punctuation.

Not with the same meaning.

• v obchodě = in the store
• do obchodu = to the store

So:

• V obchodě si vezmi košík = Take a basket in the store.
• Do obchodu si vezmi košík would mean something more like take a basket along to the store, which is not the intended idea here.

Czech makes a clear distinction between:

• location: v obchodě
• direction/movement: do obchodu

Czech word order is flexible, but it is not random. It often depends on topic, focus, and what sounds natural in context.

Starting with V obchodě sets the scene first:

• In the store, take a basket...

That makes good sense pragmatically: first the place, then the instruction.

You could also say:

• Vezmi si v obchodě košík

and it is grammatically possible, but it sounds a bit less natural in this context unless you are specifically emphasizing where to take it.

So the original order is a very normal, natural way to say it.

No, not always.

You can say both:

• vezmi košík
• vezmi si košík

But they are not exactly identical in feel.

With si, the action is presented as something you take for yourself. In many everyday situations, that is the most natural phrasing.

For example:

• Vezmi si kabát. = Put on / take your coat.
• Vezmi si židli. = Take a chair.
• Vezmi si košík. = Take a basket.

Without si, the sentence can sound more direct or more focused on the object itself.

So si is not mechanically required, but it is very commonly used and very natural here.

You would change the imperative verb:

• V obchodě si vezměte košík, protože vaše taška je už plná.

The main changes are:

• vezmi → vezměte for plural/formal you
• possibly tvoje → vaše if you are addressing someone formally or a group

So:

• informal singular: V obchodě si vezmi košík...
• plural/formal: V obchodě si vezměte košík...

Yes. Taška is a general word for bag and can refer to different kinds depending on context, such as a shopping bag, handbag, cloth bag, and so on.

That is why the sentence sounds natural: the exact kind of bag is not important. The point is simply that your bag is already full, so you should use a basket instead.

If Czech wants to be more specific, it can use other words too, for example:

• kabelka = handbag
• batoh = backpack
• igelitka = plastic bag

But taška is the broad everyday word.

Because in the present tense, Czech usually keeps the verb být (to be) in sentences like this.

So:

• taška je plná = the bag is full

Unlike in Russian, for example, Czech does not normally omit is/are in the present tense.

Therefore je is required here.

• correct: tvoje taška je už plná
• not standard: tvoje taška už plná

So this is a normal Czech predicate with je + adjective.