M'entreno al gimnàs.

M' is the shortened form of em, the 1st person singular reflexive pronoun meaning myself.

The full form would be:

Em entreno al gimnàs.

But before a vowel sound, em becomes m', so:

M'entreno al gimnàs.

This is very common in Catalan:

• m'aixeco = I get up
• m'agrada = I like
• m'entreno = I train / I work out

Yes. In this sentence, entrenar-se is being used reflexively, so it means something like to train oneself or more naturally in English, to work out.

So:

• Entreno can mean I train or I coach / I train someone, depending on context.
• M'entreno clearly means I train myself / I work out.

This reflexive form is very natural when talking about exercising.

Yes, you may hear or see Entreno al gimnàs, and it can also mean I train at the gym.

But M'entreno al gimnàs emphasizes the idea of I work out / I train myself, which is often the more natural way to express personal exercise.

Very roughly:

• Entreno al gimnàs = I train at the gym
• M'entreno al gimnàs = I work out at the gym

In everyday speech, both can appear, but the reflexive version is especially common for talking about your own fitness training.

Because a + el contracts to al in Catalan.

So:

• a = at / to
• el gimnàs = the gym
• a + el gimnàs → al gimnàs

This is just like:

• vaig al cinema = I go to the cinema
• soc al parc = I am at the park

So al gimnàs means at the gym or sometimes to the gym, depending on the verb.

In this sentence, it means at the gym.

That is because entrenar-se describes the action happening there, not movement toward it.

So:

• M'entreno al gimnàs. = I work out at the gym.
• Vaig al gimnàs. = I go to the gym.

The phrase al gimnàs itself can be translated either way in different sentences, but the verb tells you which meaning fits.

Because Catalan often drops subject pronouns when they are not needed.

The verb form entreno already tells you the subject is I.

So:

• (Jo) m'entreno al gimnàs.

Both are correct, but jo is usually omitted unless you want emphasis or contrast.

For example:

• Jo m'entreno al gimnàs, però ell corre al parc. = I work out at the gym, but he runs in the park.

It is the present tense, first person singular.

The verb is entrenar(-se), and the form is:

• (jo) m'entreno = I train / I work out

Like the present tense in English, it can express different ideas depending on context:

• a habitual action: I work out at the gym
• a general fact: I train at the gym
• sometimes a current action, though Catalan often uses other forms or context to make that clearer

So this sentence most naturally suggests a regular habit.

The accent mark in gimnàs shows which syllable is stressed.

It is pronounced with stress on the last syllable:

• gim-NÀS

Without going deeply into spelling rules, the accent helps signal the correct pronunciation and distinguishes the written form.

Yes, gimnàs is masculine, which is why it takes el:

• el gimnàs = the gym

And that is why:

• a + el = al
• al gimnàs

You usually learn the gender together with the noun:

• el gimnàs
• la piscina
• el parc

Yes. In natural English, M'entreno al gimnàs can be translated as:

• I train at the gym
• I work out at the gym

If the context is exercise and fitness, I work out at the gym is often the most natural translation. If the context is sports preparation or athletic training, I train at the gym may fit better.

You put no before the verb phrase:

No m'entreno al gimnàs.

This means:

• I don’t work out at the gym.

Catalan negation is often straightforward:

• M'entreno = I work out
• No m'entreno = I don’t work out

In everyday Catalan, you can usually make it a question just by using question intonation:

M'entreno al gimnàs? = Do I work out at the gym?

More naturally in real conversation, you might ask someone else:

• T'entrenes al gimnàs? = Do you work out at the gym?

Catalan does not always need an extra helping verb like English do. The verb form and intonation are often enough.