Learn Romanian: Vânzătorul îmi arată chitanța. - The seller is showing me the receipt.

îmi is a dative pronoun, which represents the indirect object. It answers the question 'to whom?'. The seller is showing the receipt to me. You would use the accusative pronoun mă for direct objects, for example if the seller were looking at me (vânzătorul mă vede).

Why does îmi come before the verb instead of after it?

In the present tense, short dative pronouns like îmi must be placed immediately before the conjugated verb. You cannot put them after the verb, so it must always be îmi arată.

The dictionary form of the verb is a arăta. Why does the spelling change to arată here?

This verb has a vowel change when conjugated. The first ă in a arăta changes to a regular a for the he/she/it present tense form, becoming arată.

How do the words vânzătorul and chitanța show that they mean 'the seller' and 'the receipt'?

In Romanian, definite articles like 'the' attach to the end of the noun. vânzător is a masculine noun, so it adds -ul to become vânzătorul. chitanță is a feminine noun ending in -ă, which changes to -a to become chitanța.