In English and many European languages the instrumental is expressed with a preposition:
- I eat noodles with chopsticks.
(But "with" is not dedicated to this function and has other uses such as the comitative "I eat dinner with my parents.)
Another construction for the instrumental in English would be:
- I use chopsticks to eat noodles.
In languages with a case system, there is sometimes a specific instrumental case. In others, another case my do double duty for the instrumental, or one of those cases in combination with specific prepositions.
In Chinese, the construction I know is like the second English one, using 用 for "use" in a serial verb construction.
What does Thai use? I'm in Thailand but haven't found a way to ask my local friends that they get what I'm asking (-: I've been unable to successfully Google for it so far.
I think it may use เอา and maybe in a serial verb construction, so maybe a bit like Chinese? But maybe it's like English and has more than one way to express it?