Lesa este lângă ușă.

It is a normal noun. It is capitalized only because it is the first word of the sentence.

The dictionary form is lesă, meaning leash. In this sentence, Lesa is not a person’s name.

Because lesa is the definite singular form.

In Romanian, the definite article is usually attached to the end of the noun instead of being a separate word like English the.

• lesă = a leash
• lesa = the leash

This is very common with feminine nouns ending in -ă:

• casă → casa
• ușă → ușa
• lesă → lesa

For lesa, the idea of the is built into the noun itself.

So instead of a separate word, Romanian adds the definite article at the end:

• lesă = a leash
• lesa = the leash

That is one of the biggest differences from English.

This is a very natural Romanian pattern in simple location expressions.

After prepositions such as lângă, Romanian often uses a bare noun where English would naturally say the:

• pe masă = on the table
• lângă ușă = by the door
• în casă = in the house/home

So lângă ușă sounds normal and idiomatic.

If you want to make the door more explicitly identified, Romanian often adds more information, for example:

• lângă ușa de la intrare = by the entrance door

Lângă means something like:

• near
• by
• beside
• next to

The exact English choice depends on context. In this sentence, it shows location close to the door.

So it is a basic preposition for physical proximity.

Yes. That is very common.

• este is the full form
• e is the short, very common spoken form

Both are correct:

• Lesa este lângă ușă.
• Lesa e lângă ușă.

The shorter version is especially common in everyday speech.

The diacritics matter a lot in Romanian.

• â in lângă is a Romanian vowel with no exact English equivalent
• ă in lângă and ușă is like the a in sofa or about
• ș in ușă is like sh in shoe

A rough English-style guide would be:

• lângă ≈ LUHN-guh, but with a special Romanian vowel in the first syllable
• ușă ≈ OO-shuh

That is only approximate, but it helps at the start.

This is the most neutral word order:

• subject: Lesa
• verb: este
• location phrase: lângă ușă

Romanian often uses this same basic order when simply stating where something is.

You can change the order for emphasis, for example:

• Lângă ușă este lesa.

That sounds more like The leash is by the door with extra focus on the location.

It is in the accusative, because lângă is a preposition that takes the accusative.

For this noun, the accusative form looks the same as the nominative, so you do not see any change:

• nominative: ușă
• accusative: ușă

This is normal in Romanian. The case is there grammatically, even when the form does not visibly change.

Both lesă and ușă are feminine singular nouns.

You can see that in forms like:

• lesă / lesa
• ușă / ușa

Knowing the gender helps because it affects articles and agreement elsewhere in Romanian.