你去，我就去 → I will go there if you do. (It is easier to convince me than you expected.)
jiù (就) in this sentence marks a sense of less demanding condition/easier than expectation.
你去，我才去 → I won’t go there if you don’t. (It is harder to convince me than you expected.)
cái (才) in this sentence marks a sense of more demanding condition. Chaofen Sun calls it an exclusive focus.
