Dù nhớ mã PIN, tôi cũng không nói.

It is a very common Vietnamese pattern meaning something like:

• even though ... still ...
• although ... still ...
• sometimes even if ... still ...

So in Dù nhớ mã PIN, tôi cũng không nói, the structure is:

• Dù nhớ mã PIN = even though I remember the PIN
• tôi cũng không nói = I still won’t say it / I still don’t say it

The word cũng helps create that “still / nevertheless” idea.
So dù ... cũng ... works a lot like although ..., still ... in English.

Yes, Dù tôi nhớ mã PIN, tôi cũng không nói is completely grammatical.

But Vietnamese often omits a repeated subject when it is obvious from context. Since the second clause already has tôi, the first clause can leave it out:

• Dù nhớ mã PIN, tôi cũng không nói.
• Dù tôi nhớ mã PIN, tôi cũng không nói.

Both mean the same thing.

This kind of omission is very normal in Vietnamese, especially when the subject of both clauses is the same.

Yes, nhớ can mean both:

• to remember
• to miss someone/something

Here it means to remember, because the object is mã PIN. You remember a PIN; you do not miss a PIN in this context.

Examples:

• Tôi nhớ mã PIN. = I remember the PIN.
• Tôi nhớ mẹ. = I miss my mother.

So the meaning depends on the object and context.

In this sentence, cũng adds the sense of still / nevertheless / all the same.

Compare:

• Dù nhớ mã PIN, tôi không nói.
• Dù nhớ mã PIN, tôi cũng không nói.

Both are understandable, but the version with cũng sounds more complete and natural in the dù ... cũng ... pattern.

It highlights the contrast:

• I remember it,
• but still I won’t say it.

So cũng is not just also here. In this structure, it helps express concession.

Literally, nói means say / speak / tell, depending on context.

In this sentence, không nói most naturally means:

• not say it
• not tell it
• not reveal it

Because the topic is mã PIN, English would often translate it more naturally as:

• I won’t say it
• I won’t tell you
• I won’t reveal the PIN

So the Vietnamese is slightly broader, and English chooses the best wording based on context.

Vietnamese often leaves out an object when it is obvious from context.

Here, the omitted object is understood to be the PIN, or the information about it. So:

• tôi cũng không nói = I still won’t say it / tell it

If you wanted to be more explicit, you could say things like:

• Dù nhớ mã PIN, tôi cũng không nói ra.
  = Even though I remember the PIN, I still won’t say it out loud / reveal it.

• Dù nhớ mã PIN, tôi cũng không nói cho bạn biết.
  = Even though I remember the PIN, I still won’t tell you.

So the original sentence is natural because the missing object is easy to infer.

Yes, mã PIN is very common and natural in Vietnamese.

It is similar to English expressions like PIN number, which are technically repetitive but extremely common in real usage. Vietnamese speakers regularly say:

• mã PIN
• mã số PIN sometimes
• just PIN in some contexts

So even if it feels slightly redundant from a technical point of view, it is standard everyday language.

Vietnamese verbs do not have tense endings like English verbs. So không nói does not itself mark present or future.

Depending on context, the sentence could mean:

• I don’t say it
• I won’t say it
• I’m not going to say it

In actual use, with a sentence like this, English would usually choose I still won’t say it or I still won’t tell you, because that sounds most natural.

So the tense comes from context, not from the verb form alone.

Yes. Dù can introduce either:

• a real fact: even though / although
• a hypothetical condition: even if

So depending on context:

• Dù nhớ mã PIN, tôi cũng không nói. can mean
  Even though I remember the PIN, I still won’t say it.

And in some contexts it could feel closer to:

• Even if I remember the PIN, I still won’t say it.

Usually the surrounding situation tells you whether it is factual or hypothetical.

Yes. You could say:

• Mặc dù nhớ mã PIN, tôi cũng không nói.
• Mặc dù tôi nhớ mã PIN, tôi cũng không nói.

This is grammatical and means the same basic thing.

A few general tendencies:

• dù is shorter and very common
• mặc dù is a bit more formal or explicit
• dù ... cũng ... is a very common set pattern

So for this sentence, dù sounds very natural.

Nói is understandable and natural in everyday speech, especially if the idea is simply I’m not saying it.

But if you want to sound more precise, especially in a security or formal context, Vietnamese might use:

• tiết lộ = reveal / disclose
• cho biết = let someone know / tell

For example:

• Dù nhớ mã PIN, tôi cũng không tiết lộ.
  = Even though I remember the PIN, I still won’t reveal it.

• Dù nhớ mã PIN, tôi cũng không cho bạn biết.
  = Even though I remember the PIN, I still won’t tell you.

So nói is fine, but other verbs may be more exact depending on the situation.

Yes, but some versions sound more natural than others.

The original:

• Dù nhớ mã PIN, tôi cũng không nói.

A fuller version:

• Dù tôi nhớ mã PIN, tôi cũng không nói.

You could also say:

• Tôi dù nhớ mã PIN cũng không nói.

But this is less neutral and less common as a basic learner sentence.

For learners, the safest and most natural pattern is:

• Dù + clause, subject + cũng + verb

So this sentence is a very good model to follow.

The contrast words usually get some emphasis:

• Dù nhớ mã PIN, tôi cũng không nói.

That stress helps show the concessive meaning:

• Even though I remember it,
• I still won’t say it.

In writing, Vietnamese does not need special punctuation beyond the comma here, but in speech the contrast is important.

Not very naturally.

A very literal breakdown is:

• Dù = although / even though
• nhớ = remember
• mã PIN = PIN code
• tôi = I
• cũng = still / also / nevertheless
• không nói = not say

A literal English version would be something like:

• Although remembering the PIN, I still do not say.

That sounds unnatural in English. A natural translation would be:

• Even though I remember the PIN, I still won’t say it.
• Although I remember the PIN, I’m not telling.

So it is better to understand the Vietnamese structure rather than translate each word mechanically.