Corto la cebolla en la cocina y después lavo el cuchillo.

Corto is the yo form of the verb cortar in the present tense.

• yo corto = I cut
• tú cortas = you cut
• él/ella corta = he/she cuts

So in this sentence, corto la cebolla means I cut the onion.

Spanish often leaves out subject pronouns because the verb ending already shows who is doing the action.

• Corto already means I cut
• Lavo already means I wash

So yo is not necessary. You could say Yo corto la cebolla... but that usually adds emphasis, contrast, or clarity.

Spanish uses articles much more often than English does. In this sentence, la cebolla and el cuchillo refer to specific things in the situation: the onion and the knife being used.

English might say:

• I cut the onion
• I wash the knife

But Spanish keeps the article very naturally:

• la cebolla
• el cuchillo

If you wanted to make them less specific, you could say:

• una cebolla = an onion
• un cuchillo = a knife

Yes. Cocina is a feminine noun, so it takes the feminine article la:

• la cocina = the kitchen

In Spanish, nouns have grammatical gender, so the article has to match the noun:

• la cebolla
• la cocina
• el cuchillo

This does not mean the objects themselves are biologically female or male; it is just a grammar feature.

Because la cebolla and el cuchillo are things, not people.

Spanish uses the personal a before a direct object when that object is a specific person, and sometimes a pet. For example:

• Veo a María
• Ayudo a mi hermano

But with objects like onion or knife, you do not use that a:

• Corto la cebolla
• Lavo el cuchillo

En la cocina means in the kitchen. It tells you where the action happens.

Its position is very natural here:

• Corto la cebolla en la cocina

This usually sounds like I cut the onion in the kitchen.

Spanish word order is somewhat flexible, so you could also say:

• En la cocina corto la cebolla...

That version puts more emphasis on the location.

Después by itself means afterward, later, or then.

So:

• y después lavo el cuchillo = and then I wash the knife

You use después de when it is followed by a noun, pronoun, or infinitive:

• después de comer = after eating
• después de la cena = after dinner
• después de eso = after that

So in this sentence, después alone is correct.

It can be either, depending on context.

The Spanish present tense can describe:

• something happening now
• a habitual action
• a step-by-step action, like in instructions or narration

So this sentence could mean:

• I’m cutting the onion in the kitchen and then I wash the knife
• or I cut the onion in the kitchen and then wash the knife, as part of a routine

Spanish uses the same present form for all of those ideas.

The accent mark shows where the stress goes: des-PUÉS.

Spanish spelling rules say that a word ending in a vowel, n, or s is normally stressed on the second-to-last syllable. But después is stressed on the last syllable, so it needs a written accent.

So the accent is there to show the correct pronunciation.

Yes. In most Latin American Spanish, luego and después can both mean then or afterward.

So these are both natural:

• Corto la cebolla en la cocina y después lavo el cuchillo.
• Corto la cebolla en la cocina y luego lavo el cuchillo.

There can be small regional or stylistic differences, but both are very common and correct.

Y means and. It connects the two actions:

• corto la cebolla
• después lavo el cuchillo

So the sentence is presenting a sequence:

1. I cut the onion
2. then I wash the knife

Spanish uses y just like English uses and in many cases.

A common Latin American pronunciation is roughly seh-BOH-ya.

A few helpful points:

• ce sounds like seh in most of Latin America
• bo sounds like boh
• ll is often pronounced like y in many Latin American regions

So cebolla is often pronounced close to seh-BOH-ya.

Depending on the country or region, ll may sound a little different, but that pronunciation will be understood very widely.