तोहफ़ा बाहर मत छिपाना।

Because मत is the normal way to make a negative command in Hindi.

• मत छिपाना = don’t hide
• नहीं छिपाता / नहीं छिपाती = does not hide / do not hide in a statement, not a command

So if you are telling someone not to do something, मत is the natural choice.

Yes, छिपाना is the -ना form, which is often taught as the infinitive or dictionary form.

In Hindi, though, मत + verb in the -ना form is also very common for negative instructions and warnings. So मत छिपाना is a natural way to say don’t hide.

Compare:

• मत छिपाना — common negative instruction
• मत छिपाओ — more clearly a tum command
• मत छिपाइए — polite aap command

So the -ना form here is not strange; it is a normal pattern in everyday Hindi.

Yes, the subject is omitted, and that is completely normal.

Hindi commands often leave out तुम, आप, or तू because the listener is already understood. So this sentence really means something like:

• You, don’t hide the gift outside

But Hindi usually does not need to say the you explicitly unless you want emphasis or contrast.

Because direct objects in Hindi do not always need को.

With an inanimate object like तोहफ़ा, leaving out को is very normal:

• तोहफ़ा छिपाना — hide the gift

You can sometimes hear तोहफ़े को for extra emphasis or specificity, but the plain form without को is the most neutral here.

So तोहफ़ा बाहर मत छिपाना sounds natural and idiomatic.

बाहर means outside, outdoors, or outside the place under discussion, depending on context.

Here it tells you where not to hide the gift. So it modifies the action of hiding:

• बाहर मत छिपाना = don’t hide it outside

If you wanted to be more specific, Hindi could also say things like:

• घर के बाहर मत छिपाना — don’t hide it outside the house

But on its own, बाहर is perfectly normal.

Because Hindi usually puts location words, adverbs, and other modifiers before the main verb.

A very common Hindi pattern is:

• object + place/adverb + verb

So:

• तोहफ़ा — the gift
• बाहर — outside
• मत छिपाना — don’t hide

That word order is very natural in Hindi.

Yes, somewhat. Hindi word order is flexible, but not completely free.

तोहफ़ा बाहर मत छिपाना is a natural neutral order.

You might also hear:

• बाहर तोहफ़ा मत छिपाना — puts more focus on outside
• तोहफ़ा मत छिपाना बाहर — much less natural in normal speech

So word order can shift for emphasis, but the version you have is a very normal default.

It sounds like a normal instruction or warning. It is not especially rude, but it is not the most formal or polite version either.

You can compare:

• मत छिपाना — neutral instruction / warning
• मत छिपाओ — familiar tum command
• मत छिपाइए — polite aap command
• मत छिपा — very informal, used with तू

So this sentence feels like an everyday don’t do that type of instruction.

This is a very common learner question.

• छिपना = to hide oneself / to become hidden
  This is intransitive.
• छिपाना = to hide something
  This is transitive.
• छुपाना = also to hide something
  Very common in speech; often just a variant of छिपाना

In your sentence, there is an object, तोहफ़ा, so the transitive verb is needed:

• तोहफ़ा ... मत छिपाना — don’t hide the gift

So छिपाना is the correct type of verb here.

तोहफ़ा is a loanword of Persian/Urdu origin, and फ़ represents an f sound.

So it is pronounced roughly like:

• toh-faa

In everyday Hindi writing, many people also write तोहफा without the dot, and many speakers pronounce it almost the same anyway. So both spellings are commonly seen, but तोहफ़ा is the more careful spelling if you want to show the f sound clearly.