Cậu cắt hành nhé.

In this sentence, cậu means you.

It is an informal personal pronoun, usually used:

• between friends
• between people of similar age
• in a casual, familiar setting

So Cậu cắt hành nhé. is something like telling a friend, classmate, sibling, or someone you are close to: You cut the onion, okay?

A useful warning: cậu can also mean maternal uncle in other contexts, but here it is clearly a pronoun meaning you.

Both cậu and bạn can mean you, but they feel a little different.

• bạn is often more neutral and widely usable
• cậu feels more familiar, friendly, and casual
• cậu is especially common in some speech styles, especially in the North

So using cậu here suggests the speaker and listener have some closeness. If you changed it to Bạn cắt hành nhé., it would still be understandable, but the tone would shift slightly.

Cắt means to cut, and hành refers to onion or onion-like ingredients, depending on context.

So cắt hành means cut the onion / cut onions.

In cooking, hành can refer to different things depending on the situation, such as:

• onion
• shallot
• scallion / green onion

The exact meaning depends on what food is being prepared.

Vietnamese does not use articles like English a/an/the, and it usually does not have to mark plural the way English does.

So hành can mean:

• onion
• the onion
• onions
• some onion

The context tells you which one is intended.

That is very normal in Vietnamese. Learners often want every noun to have something like the or some, but Vietnamese usually does not need that.

It is understandable and natural enough, but in cooking Vietnamese people may also say:

• thái hành
• xắt hành

These can sound more specifically like slice/chop the onion.

Very roughly:

• cắt = cut
• xắt = chop/cut up
• thái = slice

In real life, the choice depends on region, habit, and exactly how the onion is being prepared. So cắt hành nhé is fine, but a native speaker might also choose thái hành nhé or xắt hành nhé.

Nhé is a sentence-final particle that softens the sentence and makes it sound friendlier.

Here it gives a feeling like:

• okay?
• all right?
• please, yeah?
• let’s do it that way

So Cậu cắt hành nhé. is softer than just Cậu cắt hành.

Compare:

• Cậu cắt hành. → more direct, more like a plain instruction
• Cậu cắt hành nhé. → gentler, more like a friendly request or suggestion

This little word is very common in everyday Vietnamese.

It is somewhere between a request and a gentle instruction.

Because of nhé, it usually does not sound harsh. Depending on tone and situation, it could mean:

• You cut the onion, okay?
• Please cut the onion.
• Why don’t you cut the onion?

So the grammar is simple, but the actual force comes from context, relationship, and intonation.

Vietnamese often expresses politeness differently from English.

Instead of always using a direct equivalent of please, Vietnamese commonly uses:

• pronouns chosen appropriately for the relationship
• sentence-final particles like nhé
• softening words such as giúp, với, or polite intonation

So in this sentence, nhé already helps make it polite and friendly.

For example:

• Cậu cắt hành nhé. → friendly, gentle
• Cậu cắt hành giúp mình nhé. → a bit more explicitly polite/help-seeking

The word order is:

cậu + cắt + hành + nhé
subject + verb + object + sentence particle

So it follows a very familiar pattern for English speakers:

• cậu = you
• cắt = cut
• hành = onion
• nhé = softening particle

Vietnamese often keeps this straightforward subject–verb–object order.

Yes, very often.

If it is already obvious who should do it, Vietnamese can omit the subject:

• Cắt hành nhé.

That would still mean something like:

• Cut the onion, okay?
• Please cut the onion.

Including cậu makes the listener more explicit. Leaving it out can sound a little more natural in some everyday situations, especially when you are already speaking directly to the person.

A few important pronunciation points:

• cậu has a dipping/heavy tone on ậu
• cắt has a checked, sharp tone
• hành has a rising tone quality in Northern pronunciation
• nhé has a rising tone

Also:

• c and k both represent a hard k sound in Vietnamese spelling
• nh is like the ny sound in canyon
• final t in cắt is unreleased and short

If you want to sound natural, the biggest thing is not just the individual words, but the overall gentle intonation created by nhé. The sentence should usually sound light and friendly, not abrupt.