Thai stacks a small set of markers in front of the verb: certainty, obligation, จะ, and negation. They do not float. The order is fixed, it is the same order every time, and once it is automatic all of your hedging becomes free, because you are only choosing which slots to fill.
Roughly, left to right: subject, certainty (คง, อาจ), obligation (ต้อง), จะ, ไม่, verb.
- คงจะไปkʰoŋ tɕà paj
will probably go
- อาจจะไม่ไปʔàːt tɕà mâj paj
might not go
- คงไม่ไปkʰoŋ mâj paj
probably won't go
Why ไม่ is the one to watch
Negation is the only element in the stack with two available positions, and the two produce opposite sentences out of identical words. This is the week 8 point stated structurally.
Everything to the right of ไม่ is what gets negated. That is the whole rule, and it is worth saying to yourself once, because it also explains ไม่ได้ไป against ไปไม่ได้ from week 7.
- ไม่ต้องไปmâj tɔ̂ŋ paj
don't have to go
ไม่ negates ต้อง: no obligation
- ต้องไม่ไปtɔ̂ŋ mâj paj
must not go
ไม่ negates ไป: obligation to not go
The French half-advantage
French stacks too: il ne faudrait probablement pas y aller has all the same ingredients. So the idea of a stack costs you nothing.
What French does not have is an order you can rely on absolutely, because French moves things around for emphasis and Thai does not. Drill it as a fixed shape rather than as five separate words, and the sentence assembles itself.