Copacul este mort.

Because Romanian usually puts the definite article on the end of the noun.

• copac = tree
• copacul = the tree

The ending -ul is the masculine/neuter singular definite article here. So instead of a separate word like English the, Romanian attaches it to the noun.

That is a normal feature of Romanian grammar. Romanian has a postposed definite article, which means the article comes at the end of the noun instead of before it.

So:

• copac = tree
• copacul = the tree

This is one of the first things English speakers notice, because English uses a separate word, while Romanian usually uses an ending.

Este means is. It is the 3rd person singular form of the verb a fi = to be.

So in this sentence:

• copacul = the tree
• este = is
• mort = dead

Yes. In everyday Romanian, e is a very common shorter form of este.

So both are correct:

• Copacul este mort.
• Copacul e mort.

The version with este sounds a little more full or careful, while e is very common in speech.

Because adjectives in Romanian agree with the noun in gender and number.

copac is a masculine singular noun, so the adjective also takes the masculine singular form:

• masculine singular: mort
• feminine singular: moartă

So:

• copacul este mort = the tree is dead

If the noun were feminine, you would use moartă instead.

No. This is grammatical gender, not biological sex.

In Romanian, every noun belongs to a gender class, and that affects articles and adjective forms. A tree is not thought of as male in a real-world sense just because copac is grammatically masculine.

English speakers often need time to get used to this, because English usually does not mark noun gender this way.

This is the most normal and neutral word order:

• Copacul = subject
• este = verb
• mort = adjective/complement

So Copacul este mort is the standard way to say it.

Romanian can change word order for emphasis in some contexts, but for a basic statement, this is the natural order to learn first.

A rough English-style guide is:

coh-PAH-cool YES-te mort

A few notes:

• c in copacul is a hard k sound
• este is pronounced roughly YES-te
• r in mort is usually tapped or rolled lightly
• the t at the end of mort is pronounced

If you want a more exact IPA-style pronunciation, it is approximately:

/koˈpakul ˈjeste mort/

That would mean A tree is dead.

Compare:

• copacul = the tree
• un copac = a tree

So the difference is the same as in English: definite vs. indefinite.

In many situations, Copacul este mort sounds more natural if you are talking about a specific tree that both speaker and listener know.

In standard Romanian, yes, you normally keep the verb to be here.

So:

• correct: Copacul este mort.
• also common: Copacul e mort.

Unlike in some languages where the verb to be can disappear in the present tense, Romanian normally keeps it in sentences like this.

Here, mort is functioning as an adjective meaning dead.

It describes the subject copacul through the verb este:

• the tree
  • is
    • dead

So grammatically, it is a predicate adjective, just like dead in English The tree is dead.