M'agrada córrer al matí, però la meva germana prefereix caminar al vespre.

Because agradar works differently from English to like.

In Catalan, agradar is closer to to be pleasing to. So:

• M'agrada córrer literally means Running is pleasing to me
• m' = to me
• agrada = is pleasing

So Catalan expresses the idea from the point of view of the thing liked, not the person who likes it.

m' is the shortened form of em, which means to me.

• em + agrada becomes m'agrada

This shortening happens because the next word starts with a vowel. It is very common in Catalan.

Examples:

• M'agrada = I like
• M'encanta = I love
• M'interessa = It interests me

Because the thing being liked here is treated as a singular idea: córrer (to run / running).

With agradar, the verb agrees with the thing that is pleasing, not with the person.

• M'agrada córrer = I like running
• M'agraden els llibres = I like books

So:

• singular idea / one activity → agrada
• plural thing → agraden

Because Catalan often uses the infinitive to talk about activities in a general way, just like English can use to run or running.

So:

• M'agrada córrer = I like running / I like to run
• prefereix caminar = she prefers to walk / she prefers walking

After verbs like agradar and preferir, using the infinitive is very normal.

al is a contraction of a + el.

• a = at / in / to
• el = the
• a + el = al

So:

• al matí = in the morning
• al vespre = in the evening

This is a very common contraction in Catalan.

Because Catalan nouns have grammatical gender.

• matí is masculine → el matí
• vespre is masculine → el vespre
• germana is feminine → la germana

The possessive must also match the noun:

• la meva germana = my sister
• el meu germà = my brother

In Catalan, possessives are usually used together with an article.

So Catalan normally says:

• la meva germana = my sister
• el meu pare = my father
• els meus amics = my friends

This is different from English, where we usually do not use the with possessives.

però means but.

It connects two contrasting ideas:

• M'agrada córrer al matí = I like running in the morning
• però la meva germana prefereix caminar al vespre = but my sister prefers walking in the evening

So it works very much like English but.

prefereix is the 3rd person singular present tense of preferir.

It means:

• he/she prefers

Here it refers to la meva germana, which is she:

• la meva germana prefereix = my sister prefers

This is why the verb is not prefereixo (I prefer) or preferim (we prefer).

Usually yes, vespre is translated as evening.

A useful time vocabulary comparison is:

• matí = morning
• tarda = afternoon
• vespre = evening
• nit = night

Depending on context, vespre can feel a bit like the period between late afternoon and night.

Yes. In English, both are natural:

• I like running
• I like to run

Catalan M'agrada córrer can correspond to either one. The Catalan sentence does not force exactly one of those English versions.

The same applies to:

• prefereix caminar = she prefers walking / she prefers to walk

You would change both the noun phrase and the verb form.

• la meva germana prefereix = my sister prefers
• les meves germanes prefereixen = my sisters prefer

So the full sentence would become:

M'agrada córrer al matí, però les meves germanes prefereixen caminar al vespre.

Notice:

• la → les
• meva → meves
• germana → germanes
• prefereix → prefereixen

A rough pronunciation guide for an English speaker:

• M'agrada ≈ muh-GRA-thuh or muh-GRA-duh
  
  • The exact sound of d can vary by accent.
• córrer ≈ KOR-rer
• matí ≈ muh-TEE
• però ≈ peh-RO
• prefereix ≈ preh-feh-RAYSH
• caminar ≈ kuh-mee-NAR
• vespre ≈ BES-pruh

A few helpful points:

• The written accent shows the stressed syllable: córrer, matí, però
• The rolled or tapped r may take practice
• Pronunciation varies somewhat across Catalan-speaking regions

Yes, Catalan sometimes allows other time expressions depending on style and region, but al matí is a very standard and natural way to say in the morning.

Similarly:

• al vespre = in the evening
• a la nit = at night

These short time phrases are worth learning as fixed expressions.