L'entrenador està sol.

Because Catalan shortens the definite article before a vowel. Here, el + entrenador becomes l'entrenador. So the apostrophe shows that the article is still there, just contracted.

Since entrenador is masculine singular, l' stands for el in this sentence.

Catalan often uses estar for a temporary state or condition, and being alone is usually treated that way. So L'entrenador està sol means the coach is alone at that moment or in that situation.

Using és here would sound unnatural in standard Catalan. In general:

• ser = identity, essential characteristics
• estar = states, conditions, locations

The accent marks the stressed syllable: es-TÀ. It is part of the correct spelling of the 3rd person singular form of estar.

So:

• jo estic
• tu estàs
• ell/ella està

Because adjectives in Catalan agree in gender and number with the noun they describe.

Entrenador is masculine singular, so the adjective is sol. If the noun were feminine, it would be sola:

L'entrenadora està sola.

Here it means alone.

Catalan sol can be:

• a noun meaning sun: el sol
• an adjective meaning alone: està sol

In L'entrenador està sol, it is clearly an adjective describing the coach.

Its most direct meaning is alone or by himself. Depending on context, it can sometimes suggest loneliness, but it does not automatically mean lonely in an emotional sense.

If you want to make the emotional meaning clearer, Catalan often uses something like se sent sol = he feels lonely.

Yes. Catalan often drops subject pronouns and even leaves out the noun when the context is clear.

So if everyone already knows you are talking about the coach, you could simply say:

Està sol.
= He is alone.

But L'entrenador està sol is perfectly normal when you want to state the subject explicitly.

Normally, no. For the coach, Catalan usually needs the article: l'entrenador.

So:

• L'entrenador està sol. = The coach is alone.
• Un entrenador està sol. = A coach is alone.

A bare Entrenador està sol would sound unnatural in standard Catalan.

A rough pronunciation is:

len-truh-nuh-DOR es-TA SOL

A few useful points:

• l'entrenador flows together smoothly
• està is stressed on the last syllable
• the r in entrenador is not like a strong English r
• sol is a short one-syllable word

The exact pronunciation varies by dialect, but that approximation is good enough to start.

No. This is a very normal Catalan sentence pattern:

subject + verb + adjective

So:

• L'entrenador = subject
• està = verb
• sol = adjective complement

It is the same basic structure as in English: The coach is alone.