Learn Romanian: Casierul a numărat banii. - The cashier counted the money.

The base word is ban (coin). The first -i makes it plural (bani, meaning money). The second -i is the masculine plural definite article ('the'). This second -i turns the normally whispered plural ending into a fully pronounced 'ee' vowel sound.

Why don't we use the direct object marker 'pe' before banii since it is a specific, definite object?

In Romanian, you only use the preposition pe before direct objects that are people or proper names. Because banii is an inanimate object, it never takes pe, even when it has a definite article.

In English, 'money' is an uncountable singular noun. Is it singular or plural in Romanian?

It is strictly plural. The word bani literally means 'coins' (a single ban is one-hundredth of a Leu). Because of this, you must always use plural verbs and adjectives when describing it, unlike the singular 'money' in English.

How is the definite article attached in the word casierul?

The base noun is casier (masculine singular). To say 'the cashier', you add the specific masculine definite article -ul directly to the end of the word, creating casierul.