Breakdown of ansyoubangou wo tomodati ni mo osiete ha ikemasen.
Questions & Answers about ansyoubangou wo tomodati ni mo osiete ha ikemasen.
を marks the direct object of the verb – the thing that is being acted on.
- 暗証番号を教える literally = to teach/tell the PIN
- So 暗証番号を = the PIN (as the thing you tell)
You can’t use が here, because 暗証番号 is not the subject; it’s the thing being told.
The verb 教える takes:
- the thing being taught/told with を
- the person you teach/tell with に
So:
- 暗証番号を友達に教える
= to tell the PIN *to a friend*
Think of it like English “teach/tell something to someone”:
- something → を
- someone → に
Using 友達を with 教える would be wrong in this sense; 友達を教える would sound like “teach the friend (as a subject)”, which is not what you mean.
も basically means also / even.
In a negative sentence like this, 友達にも … いけません often has the nuance:
- “You must not tell it, not even to friends.”
So:
- 友達に = to (your) friends
- 友達にも = even to (your) friends / to friends, too
The sentence is implying:
You mustn’t tell your PIN to anyone at all – including (or not even) your friends.
Here は is part of a fixed grammar pattern:
- Vてはいけません = you must not V / it is not allowed to V
Literally, it comes from:
- Vては + いけません
where いけません ≈ “is no good / is not acceptable”
So 教えてはいけません is:
- 教えて (the て-form of 教える)
- は (attached to that て-form)
- いけません (polite “not allowed”)
You shouldn’t think of this は as a normal topic marker here; just remember 〜てはいけません as one unit meaning “must not do ~”.
The て-form is required by the pattern:
- Vてはいけません = must not V
So:
- Dictionary form: 教える (to teach / to tell)
- て-form: 教えて
- Pattern: 教えてはいけません = You must not tell/teach (it).
You cannot say 教えないはいけません; that’s ungrammatical.
For this type of prohibition with いけません, you always use:
- Vて + は + いけません
教える has two main meanings:
- to teach (a skill, subject, etc.)
- to tell / to inform (someone of some information)
In security-related sentences like this, 教える almost always means “to tell (information)”:
- 暗証番号を教える = to tell (someone) your PIN
So in context, the sentence means:
- You must not tell your PIN to your friends (either / even to your friends).
“Teach your PIN” would sound strange in English; tell / share is the natural translation.
暗証番号 literally:
- 暗証 = personal code / verification by something secret
- 番号 = number
So 暗証番号 = a secret number used to verify you, i.e.:
- a PIN (like for a bank card or phone)
- sometimes used for numeric passwords or unlock codes
If it’s a general password (letters + numbers), Japanese often uses パスワード instead.
So 暗証番号 is especially natural for PIN codes or numeric unlock codes.
Japanese often omits the subject when it’s clear from context.
In:
- 暗証番号を友達にも教えてはいけません。
there is no explicit I/you/people. The subject is understood from context as:
- you (when talking or writing to the reader/listener), or
- people in general (One must not… / You shouldn’t…).
So a natural English translation supplies you:
- You must not tell your PIN even to friends.
But in Japanese it’s simply left out because it’s obvious from the situation.
Yes, both orders are grammatical:
- 暗証番号を友達にも教えてはいけません。
- 友達にも暗証番号を教えてはいけません。
The basic meaning is the same. Word order in Japanese is relatively flexible as long as:
- The particles stay attached to the right words, and
- The verb comes at the end.
Putting 友達にも first may slightly emphasize friends (“Even to friends, you must not tell your PIN”), but the difference is small in everyday use.
〜てはいけません is fairly strong:
- Literally: It is not acceptable if you do ~.
- Usual translation: must not / may not / not allowed to
In everyday speech, depending on tone and context, it can sometimes feel like strong “shouldn’t”, but grammatically it’s closer to prohibition:
- ここでタバコを吸ってはいけません。
= You must not smoke here. / Smoking here is not allowed.
For a softer, more request-like prohibition, you might hear:
- 〜ないでください = Please don’t ~.
Both can be translated as “Don’t tell (it)”, but the nuance is different:
教えてはいけません。
- rule-based, objective prohibition
- “You must not tell (it). It is not allowed.”
教えないでください。
- polite request
- “Please don’t tell (it).”
In your sentence, because it’s about security rules (PIN numbers), 教えてはいけません fits well: it sounds like an official or strict guideline rather than a personal request.