Original Post by John Boegehold
Something I’ve never gotten clear is if there’s such a thing as a “double negative” in Thai. For example, In English, saying “It’s not unusual that Bob comes to the office late,” gets the point across. It may not be technically grammatically correct, but everyone understands the concept. In Thai, I get ปกติ, I get ผิดปกติ, so with my American brain, I’d assume that ไม่ผิดปกติ would be the double negative. Of course, to preserve my sanity I stopped assuming things when it comes to Thai a long time ago.
The double negative “Not unusual” doesn’t really mean “usual” the way it’s used as a figure of speech in English. It’s somewhere in between. “It’s usual for Bob to be late” means he’s probably late 98% of the time. “It’s unusual for Bob to be late” means he might be late 2% of the time. “It’s not unusual for Bob to be late” might mean he could be late 25-30% or whatever. It’s a shade of gray that isn’t correct grammatically but understood when used. I’m definitely starting to get that it a term of art not used in Thai อิอิ
Reply by Rikker Dockum
What’s clear is that, like standard English, Thai has no negative concord (where multiple negatives strengthen each other, rather than cancel each other out).
And while you can’t simply string ไม่ together twice in a row, as mentioned, one thing you can do is preface pretty much any negated verb with ไม่ใช่ว่า… “It’s not that I didn’t…/I don’t _not_…” which weakens the negativity of the next statement without canceling it out.
ไม่ใช่ว่าไม่ชอบ “It’s not that I don’t like it / I don’t _not_ like it,”
Do a quick Google search for “ไม่ใช่ว่าไม่” in quotes and you’ll get loads of examples.
ไม่ใช่ว่าไม่เห็นด้วย.. แต่.. “I don’t disagree, but…”
ไม่ใช่ว่าไม่รัก.. เพียงแต่.. “I don’t _not_ love you, it’s just that…”
Etc. So that’s one way you can use a double negative in Thai. See also common phrases like ไม่เลว, parallel with English “not bad,” as a weakened negative, but not equivalent to ดี, of course (and perhaps directly influenced by the English usage, since the normal way to say “bad” in Thai is really ไม่ดี, and เลว left un-negated is stronger than English “bad.”)
Going into a bit deeper syntactic analysis, we can split negation in Thai down like this:
ไม่ – negates a verb/adjective
ไม่ใช่ – negates a noun phrase
ไม่ใช่ว่า – negates a clause
So looking at those combinatorially:
ไม่ + verb phrase = clause
ไม่ใช่ + noun phrase = clause
So we would expect ไม่ใช่ว่า to be able to negate either of those, as two types of embedded clauses:
1. [ไม่ใช่ว่า [ไม่ + verb phrase]]
2. [ไม่ใช่ว่า [ไม่ใช่ + noun phrase]]
And we can demonstrate this using Google:
ไม่ใช่ว่าไม่รู้ “It’s not that (I) don’t know…” (Type 1)
ไม่ใช่ว่าไม่ใช่ฤดูท่องเที่ยว “It’s not that it’s not tourist season” (Type 2)
So the reason ไม่ไม่ fails should be clear: you can’t negate a clause with ไม่, and since you’ve created a clause with the first ไม่, a second ไม่ in front won’t do. You have to use clausal negation ไม่ใช่ว่า to negate that, and then it’s acceptable. It’s not uncommon at least (see what I did there? :P).