Casiera îmi dă timbrul și o chitanță.

Romanian usually puts the definite article at the end of the noun, not before it as English does.

• casieră = cashier
• casiera = the cashier
• timbru = stamp
• timbrul = the stamp

The ending changes depending on the noun’s gender and shape:

• many feminine singular nouns take -a
• many masculine/neuter singular nouns take -ul or -l

So casiera and timbrul both contain the, just in different forms.

îmi means to me.

It is an indirect object pronoun: the person receiving something. So:

• Casiera îmi dă... = The cashier gives me...
• literally: The cashier gives to me...

Romanian often uses this short pronoun instead of a separate word like English to.

îmi is the normal, unstressed form used in an ordinary sentence.

mie is the stressed form, used for emphasis or contrast, often together with îmi:

• Casiera îmi dă timbrul. = neutral
• Casiera îmi dă mie timbrul. = The cashier gives the stamp to me (emphatic)

So in a plain sentence, îmi is exactly what you expect.

dă is the 3rd person singular present of a da, meaning to give.

So dă can mean:

• he gives
• she gives
• it gives

In this sentence, it means she gives, because casiera is feminine.

A few useful forms of a da:

• eu dau = I give
• tu dai = you give
• el/ea dă = he/she gives

Because o chitanță means a receipt, not the receipt.

• o chitanță = a receipt
• chitanța = the receipt

So the sentence contrasts:

• timbrul = the stamp (specific, definite)
• o chitanță = a receipt (not presented as a specific known one)

Also, o is used because chitanță is a feminine singular noun.

Romanian usually does not need a separate word like English to in this structure. The idea of to me is built into the pronoun îmi.

So:

• îmi dă = gives me
• literally: gives to-me

This is very normal in Romanian. English uses a separate word; Romanian often uses a special pronoun form instead.

Because short object pronouns like îmi normally go before a conjugated verb in Romanian.

So:

• îmi dă = standard word order

This is a common pattern:

• îmi spune = tells me
• îți dau = I give you
• ne vede = sees us

One important exception is the positive imperative, where the pronoun is attached after the verb:

• Dă-mi timbrul! = Give me the stamp!

Yes, if the context already makes it clear who she is.

Romanian often leaves the subject unspoken when it is already understood. So:

• Îmi dă timbrul și o chitanță. = She’s giving me the stamp and a receipt.

Including casiera makes the subject explicit: the cashier.

timbru most often means stamp, but the exact kind depends on context.

It can refer to:

• a postage stamp
• a fiscal/revenue stamp
• sometimes other kinds of official stamps, depending on the situation

In a sentence like this, a learner will usually understand it simply as stamp.

A few important pronunciation points:

• ș = sh as in ship
• ț = ts as in cats
• ă = a short neutral vowel, like the a in sofa
• î = a Romanian vowel with no exact English equivalent; a tight central sound
• ch before i or e sounds like k, so chitanță starts with kee-

A rough pronunciation of the whole sentence is:

ka-see-EH-ra îm' də TIM-brul shee o kee-TSAN-tsuh

That is only approximate, but it is a good start.