The main function of the adverb c´ai (才) is to signal an exclusive condition.
For instance, the sentence 你去我才去 (n˘ı q`u w˘o c´ai q`u/ I will go only if you go.) implies that there is only one situation in which the speaker would agree to go.
Therefore, c´ai (才) can be used in counter-expectational Linking.
→ 他敢吃，我才敢吃 (tā gǎn chī，wǒ cái gǎn chī/ I won't eat it unless he eats it.)
c´ai (才) also suggests a sense of lateness of the event that should have taken place sooner.
→ 他明天才來 (t¯a m´ıngtian c´ai l´ai/ He will not come until tomorrow.)
Reference: Chinese: a linguistic introduction by Chao Fen Sun