Cuando termino de trocear las verduras, mi padre empieza a aliñar la ensalada.

Because terminar normally needs de before an infinitive when it means to finish doing something.

• terminar de trocear = to finish chopping
• terminar de comer = to finish eating
• terminar de estudiar = to finish studying

So in this sentence:

• Cuando termino de trocear las verduras... = When I finish chopping the vegetables...

Without de, it would sound incorrect here.

Because empezar usually takes a + infinitive.

• empezar a cocinar = to start cooking
• empezar a hablar = to start speaking
• empezar a aliñar = to start dressing/seasoning

So:

• mi padre empieza a aliñar la ensalada = my father starts dressing the salad

This is a very common pattern in Spanish:

• comenzar a + infinitive
• aprender a + infinitive
• ir a + infinitive

Not exactly.

• cortar = to cut in a general sense
• trocear = to cut into pieces / chop into chunks

So trocear is more specific. It suggests dividing something into smaller pieces.

For example:

• cortar una cebolla = to cut an onion
• trocear una cebolla = to chop an onion into pieces

In cooking, trocear is very natural.

In this context, yes: aliñar la ensalada means to dress/season the salad.

In Spain, aliñar is very common for adding things like:

• olive oil
• vinegar
• salt

So it can mean:

• to dress
• to season

A salad is often aliñada with oil, vinegar, and salt.

This verb is especially common in Spain. In other Spanish-speaking regions, people may also say aderezar.

Because here cuando is being used for a habitual or repeated action, not a future one.

• Cuando termino de trocear las verduras, mi padre empieza a aliñar la ensalada. = Whenever/When I finish chopping the vegetables, my father starts dressing the salad.

This sounds like a routine.

But if you are talking about a specific future event, Spanish normally uses the subjunctive after cuando:

• Cuando termine de trocear las verduras, mi padre empezará a aliñar la ensalada. = When I finish chopping the vegetables, my father will start dressing the salad.

So:

• cuando + indicative → habitual, general, repeated, or present/past reality
• cuando + subjunctive → future or not-yet-completed action

Because Spanish often uses the present tense for habitual actions and routines.

So:

• Cuando termino de trocear las verduras... literally looks like When I finish chopping the vegetables... but the meaning is more like:
• Whenever I finish chopping the vegetables...
• When I’m done chopping the vegetables...

This is normal Spanish usage. The present tense can describe things that regularly happen.

Because Spanish often leaves out subject pronouns when the verb ending already shows who the subject is.

Here we have:

• termino → clearly I finish
• empieza → clearly he/she starts

So Spanish does not need:

• yo termino
• él empieza

The sentence could include them for emphasis:

• Cuando yo termino de trocear las verduras, mi padre empieza a aliñar la ensalada.

But normally they are omitted.

Because the sentence begins with a subordinate clause:

• Cuando termino de trocear las verduras, ...

Then comes the main clause:

• mi padre empieza a aliñar la ensalada.

In English, we also usually put a comma after an introductory when clause:

• When I finish chopping the vegetables, my father starts dressing the salad.

In Spanish, this comma is also natural and standard here.

Spanish uses definite articles much more often than English.

So even where English might simply say:

• chopping vegetables
• dressing the salad

Spanish naturally says:

• trocear las verduras
• aliñar la ensalada

The articles help identify the things involved, often as part of the situation already understood by the speakers.

This is very common in Spanish, especially with food, body parts, and general nouns in context.

Not with the same meaning.

• termino de trocear = I finish chopping
• acabo de trocear = I have just chopped / I just finished chopping

So acabar de + infinitive usually means to have just done something, not simply to finish doing it.

Compare:

• Cuando termino de trocear las verduras... = When I finish chopping the vegetables...

• Acabo de trocear las verduras. = I’ve just chopped the vegetables.

So they are related, but not interchangeable in every context.

Yes, but the meaning changes a bit.

• cortar = to cut in a general way
• trocear = to cut into pieces/chunks
• picar = to chop finely / mince in many contexts

So depending on the size of the pieces:

• trocear las verduras → cut into pieces
• picar las verduras → chop them more finely
• cortar las verduras → just cut the vegetables

In a cooking context, all three are possible, but trocear gives a more specific image.

Yes, it is very typical of Spain Spanish.

In Spain, aliñar is a very normal verb for salads and similar foods.

In other regions, you may also hear:

• aderezar la ensalada
• condimentar la ensalada in some contexts

But if you are learning Spanish from Spain, aliñar la ensalada is a great expression to know.

It literally means my father, but in many contexts it can be translated naturally as my dad, depending on tone.

• mi padre = neutral standard expression
• mi papá = more affectionate or informal in many places
• mi viejo = colloquial in some regions, but not standard everywhere

In Spain, mi padre is very common in ordinary speech and does not necessarily sound overly formal.