If 'Go not' is improper, why 'Mention not' is proper?

Question

The commonest answer I get after telling someone 'Thank you' is 'Mention not.'

If I answer something like this, many would turn this sentence down

That place is so exciting, I want to go ~ Go not. There could be a snake.

But then if I answer this in a traditional way, there's no problem!

Thank you. ~ Mention not. You can ask for such favor any time.

Note: 'Go not' is just one example. I mean all such verb to be used with not. For instance, talk not, walk not, like not, study not, sleep not instead of don't talk, don't like, don't study... and so on.

Answer 1

Go not is archaic. It's ungrammatical in Modern English, but people are familiar with this construction as an archaism and will understand anyway. To put it another way, it's grammatical, but the grammar it's part of is that of an older form of English.

Here's a simplified timeline:

• In Middle English (1150-1500 AD), the post-verbal negator not developed, at first appearing with and then replacing the older pre-verbal negator ne. (This is an example of the Jespersen Cycle.)
• In Early Modern English (1500-1700 AD), the modern version of do-support gradually developed, appearing more and more frequently with negative declaratives, with not following do rather than the main verb.
• In Modern English (1700 AD to present), do-support became obligatory in negative declaratives with no other auxiliary verbs, probably roughly sometime in the 1800s, effectively restricting verbal negation to auxiliary verbs (Do not walk rather than Walk not).

Afterwards, the narrow distribution of the reduced form n't allowed it to be reanalyzed as an inflectional affix, which is particularly noticeable in inverted sentences. The affix -n't inverts along with the auxiliary, but the independent word not does not, so Doesn't he walk corresponds to the uncontracted form Does he not walk, not to *Does not he walk—although to this day Heavy NP Shifts result in a similar structure from time to time.

*Mention not is ungrammatical for another reason as well. Mention is transitive, so in the older grammar it should instead be Mention it not, corresponding to the modern Don't mention it.

Of course, if Mention not is really that common in Indian English, then there's nothing wrong with using it. But when I searched, I was unable to find any examples in Corpus of Global Web-Based English (GloWbE); I found only one result listed under Indian English, and that example was a false positive.

Answer 2

The construction of verb not is used as a poetic or litereary form or sometimes for emphasis. It is not in widespread use.

A recent author who used the form regularly is Douglas Adams, particularly in The Hitchhiker's Guide to the Galaxy. Quotes such as "I speak not of future events" are scattered through the series. There is also the variant "A mere abacus! Mention it not.".

You do see the construction used with a number of verbs, I have seen "Go not there" as a warning of danger. However, I have never come across the other examples that you suggest; Walk not, sleep not, etc.