Công thức ở trong email.

Công thức can mean formula, recipe, or sometimes a set method/pattern, depending on context.

So if the meaning has already been given to you, the important thing to know is that this Vietnamese noun is a bit broader than any single English word. You choose the best English translation from context.

Vietnamese often does not use a separate verb like English is in simple location sentences.

In Công thức ở trong email, the location expression does the job:

• ở marks location
• trong means in/inside

So the sentence naturally means that the formula or recipe is in the email.

Using là here would not be natural. Là is not the normal word for location.

This is a very common learner question.

• ở = at, in, located at
• trong = in, inside

Together, ở trong means something like in / inside. It is natural Vietnamese, and it adds a clear sense of location.

In many situations, trong email would also work. So:

• Công thức ở trong email = fully natural
• Công thức trong email = possible, but can sound more compressed or less clearly like a full sentence

Vietnamese usually does not require articles the way English does.

So công thức could mean:

• a formula
• the formula
• a recipe
• the recipe

The exact meaning depends on context.

If a speaker wants to be more specific, they can add other words, for example:

• một công thức = a formula / one formula
• công thức này = this formula
• công thức đó = that formula

It can absolutely work as a full sentence, especially in speech, texting, or short written communication.

It sounds especially natural as an answer to a question like:

• Công thức ở đâu? = Where is the formula?

In longer or more explicit writing, a speaker might also say:

• Công thức nằm trong email.
• Công thức có trong email.

Those versions can sound a bit more explicit, but the original sentence is still fine.

Sometimes yes, but the nuance changes a little.

Công thức ở trong email is more clearly a complete statement meaning that the formula is located in the email.

Công thức trong email can sound more like a noun phrase:

• the formula in the email

In conversation, people may still understand it as a full statement from context, but ở trong makes the sentence structure clearer for a learner.

Yes, email is very commonly used in Vietnamese.

A more formal or fully Vietnamese expression is thư điện tử, but in everyday life most people simply say email. That makes the sentence sound modern and natural.

So:

• email = common in everyday speech and writing
• thư điện tử = more formal or official

Vietnamese usually puts the thing being talked about first, then gives information about it.

So the pattern here is:

• Công thức = the formula / recipe
• ở trong email = in the email

This is very similar to English word order:

• The formula is in the email

You can also rearrange things in Vietnamese for a different focus. For example:

• Ở trong email có công thức.

That means something closer to:

• There is a formula in the email.

Both are possible, but the focus is slightly different.

Ở is often one of the hardest parts for English speakers.

It has:

• the vowel ơ, which does not exist in English in exactly the same way
• the hỏi tone

So even if you know the grammar, this word may still feel difficult to say at first.

The other words are usually easier:

• công has a level tone
• thức has a sắc rising tone
• trong has a level tone

If you are practicing aloud, it is helpful to treat ở as the main pronunciation challenge in this sentence.