Já si vždycky beru účtenku a dávám ji do tašky.

That’s true: Czech often leaves out subject pronouns because the verb ending already shows the person.

• beru = I take / I’m taking
• dávám = I put / I’m putting

So the sentence could simply be:

Vždycky si beru účtenku a dávám ji do tašky.

Adding já gives a bit of emphasis, contrast, or just a more explicit tone. It can feel like:

• I always take the receipt...
• As for me, I always take the receipt...

It is not required, but it is perfectly natural.

Si is the short form of the reflexive/dative pronoun, and here it roughly means for myself.

So beru si účtenku is more like:

• I take the receipt for myself
• I take/keep the receipt

In natural English, si is often not translated at all. It just helps make the Czech expression sound right.

Compare:

• beru účtenku = I take the receipt
• beru si účtenku = I take the receipt for myself / I take and keep it

With things like receipts, food, clothes, seats, etc., brát si is very common.

In standard Czech, short unstressed words like si usually go very early in the sentence, typically in the second position.

That is why:

• Já si vždycky beru... sounds natural
• Vždycky si beru... sounds natural

But:

• Já vždycky si beru... sounds unnatural in standard Czech

So this is largely a word-order rule involving short clitic words like si, se, mi, ti, etc.

Because the sentence describes a habit or repeated action: I always take the receipt.

• beru is imperfective
• vezmu is perfective

In Czech, the present tense of an imperfective verb is used for:

• ongoing action
• repeated/habitual action

So:

• beru si účtenku = I take / I’m taking / I usually take the receipt

But:

• vezmu si účtenku usually means I will take the receipt or I’ll take the receipt once

Since vždycky means always, the habitual imperfective beru is the right choice.

Because účtenku is the accusative singular form, and here receipt is the direct object of the verb beru si.

Base form:

• účtenka = receipt

Accusative singular:

• účtenku

This is a normal pattern for many feminine nouns ending in -a:

• kniha → knihu
• taška → tašku
• účtenka → účtenku

So:

• beru si účtenku = I take the receipt

Ji means it here. It refers back to účtenku.

So:

• dávám ji do tašky = I put it into the bag

Since účtenka is a feminine noun, the pronoun is feminine too.

Using ji avoids repeating the noun:

• dávám účtenku do tašky = I put the receipt into the bag
• dávám ji do tašky = I put it into the bag

Both are possible, but using the pronoun is very natural.

Here ji is the normal short accusative form meaning her/it.

In this sentence, the verb dávat takes a direct object, so accusative is needed:

• dávám ji = I put it

Learners often confuse ji and jí because they look similar, but here ji is the standard choice.

For the same reason as beru: the sentence describes something habitual.

• dávám = imperfective
• dám = perfective

So:

• dávám ji do tašky = I put it into my bag / I’m putting it into my bag / I habitually put it there
• dám ji do tašky = I’ll put it into my bag / I’ll put it in once

Because the sentence means I always do this, Czech uses the imperfective dávám.

Because do means into, and after do, Czech uses the genitive case.

Base form:

• taška = bag

After do:

• do tašky = into the bag

So the -y ending here does not mean plural. It is simply the genitive singular form.

This is a very common beginner question, because -y often looks plural, but case endings can create the same form.

Compare:

• taška = bag
• do tašky = into the bag
• tašky = bags / of the bag, depending on context

The preposition tells you which meaning is intended.

Because the sentence expresses movement into the bag, not location in the bag.

• do tašky = into the bag
• v tašce = in the bag

So:

• Dávám ji do tašky = I put it into the bag
• Je v tašce = It is in the bag

This is the same kind of difference as English into vs in.

Here it clearly means a habit, because of vždycky = always.

So the sentence means something like:

• I always take the receipt and put it into my bag.

Without vždycky, the present tense could be understood in more than one way depending on context:

• Beru si účtenku a dávám ji do tašky.
  • I’m taking the receipt and putting it into my bag.
  • I take the receipt and put it into my bag.

Czech imperfective present can cover both ongoing and habitual meaning, and the context tells you which one is meant.

Yes, but it is small.

• vždycky = very common in everyday speech
• vždy = also means always, but can sound a bit more formal, literary, or fixed-expression-like

In this sentence, vždycky sounds very natural and conversational.

So:

• Já si vždycky beru účtenku... = very natural spoken Czech
• Já si vždy beru účtenku... = also correct, but slightly different in tone