Because Romanian usually puts the definite article at the end of the noun.
So -a here is not just part of the noun stem. It shows that the noun is definite.
This is very different from English, where you would use a separate word, the.
Romanian usually uses an attached definite article instead of a separate word.
Compare:
And:
So instead of putting the before the noun, Romanian often adds it to the end.
This is a very common learner question.
In Romanian, after a preposition, a bare noun like portofel can sometimes sound natural even when English would use the wallet. Romanian often leaves the noun without the definite article in common location expressions, especially when the context already makes the meaning clear.
So:
If you want to make the wallet clearly definite and specific, you would usually say something like în portofelul meu, în portofelul lui, and so on.
So the sentence as given is natural, but the exact English article can depend on context.
În means in or inside.
The vowel î is a Romanian sound that English does not really have. It is a central, tight vowel. A good beginner approach is:
Also, în is pronounced as one syllable.
So în portofel means in the wallet / in a wallet.
Yes. The base noun is bancnotă, which is feminine.
That matters because adjectives and some other words must agree with it.
For example:
The ending -ă in the basic form bancnotă is a common sign of a feminine noun, though not every feminine noun ends that way.
The given word order is the most neutral and straightforward one:
This is basically:
Romanian word order is fairly flexible, so other orders are possible for emphasis, but they do not sound as neutral.
For example:
This can sound more marked, as if you are emphasizing the location.
So for a learner, the given order is the safest default.
It is capitalized because it is the first word of the sentence.
Romanian capitalization works much like English in this respect. Common nouns such as bancnotă and portofel are not normally capitalized in the middle of a sentence.
The dictionary forms are:
So the sentence uses:
This is useful because Romanian dictionaries usually list nouns in the indefinite singular form, not the definite one.
Normally, no. In standard Romanian, este is usually kept in a sentence like this.
So:
Dropping este would not be standard here.
That is different from some languages where the present form of to be is often omitted. Romanian generally keeps it.
You would usually use the indefinite article o for a banknote:
Compare:
So the difference between bancnota and o bancnotă is the difference between the banknote and a banknote.