Decimos buen provecho antes de comer.

Decimos is the present tense, nosotros form of decir (to say).

• yo digo = I say
• tú dices = you say
• él/ella dice = he/she says
• nosotros decimos = we say

In this sentence, decimos means we say, but it can also sound more general, like this is what people say.

This is because bueno becomes buen before a singular masculine noun.

• un libro bueno = a good book
• un buen libro = a good book

Since provecho is a singular masculine noun, Spanish uses buen before it:

• buen provecho

This shortening is called apocopation.

Buen provecho is a very common expression said around mealtimes, similar to enjoy your meal or bon appétit.

It does not literally function like a full sentence here. It is more of a fixed social expression. That is why learners should think of it as a chunk:

• buen provecho

rather than analyzing it word by word every time.

Because buen provecho is being used as a set expression, not as a regular noun phrase.

Compare:

• Deseo buen provecho a todos. = I wish everyone a good meal / enjoy your meal.
• El provecho de algo = the benefit of something.

In the sentence Decimos buen provecho antes de comer, the phrase is just the expression people say, so no article is needed.

Because after antes, Spanish normally uses de before an infinitive.

So the correct pattern is:

• antes de + infinitive

Examples:

• antes de salir = before leaving
• antes de estudiar = before studying
• antes de comer = before eating

So antes comer is not correct here.

Because after the preposition de, Spanish uses the infinitive when speaking generally.

• antes de comer = before eating / before we eat

Using comemos would require a different structure, such as:

• antes de que comamos = before we eat

So:

• antes de comer = more general and simple
• antes de que comamos = uses a conjugated verb and a new clause

Yes. That would also be natural.

There is a small difference in style:

• Decimos buen provecho... = We say... / People say...
• Se dice buen provecho... = One says... / It is said...

Both can express a general custom.
Decimos sounds a little more direct and inclusive, while se dice sounds a little more impersonal.

It is widely understood across Latin America, and it is a very common thing to say before eating or when someone is eating.

However, usage can vary somewhat by country, family, and situation. In many places, people say it:

• before everyone starts eating
• when passing by people who are already eating
• as a polite social phrase

So it is a very useful expression for learners.

It can mean either one in English, depending on how naturally you want to say it.

Spanish often uses the infinitive in places where English may use either:

• before eating
• before we eat

In this sentence, both are good ways to understand antes de comer.

Yes. Spanish often uses the present tense to talk about customs, routines, and general truths.

So Decimos buen provecho antes de comer means something like:

• We say buen provecho before eating
• People say buen provecho before eating

This is a normal use of the present tense in Spanish.