But could is not always past. We also use could for possible actions now or in the future, especially to make suggestions. For example:
美斯既usage係指possible咋 姐係夏撚今日都有機會贏,唔係指個獎係佢,香港學生黎講,你英文都算差個批,睇01係啱你水準
利申:英文系 + 以前幫人補過中六DSE英文
source: Cambridge Grammar in use intermediate Unit 27