make efforts to do sth.为什么effort要加s?

make efforts to do sth.为什么effort要加s? make efforts to do sth.为什么effort要加s,它是可数名词吗? make an effort to do sth 和 make every effort to do sth 的区别 make efforts/an effort to do和in a common effort effort的用法?是什么时候单数 什么时候复数?make great efforts to do 还是effrot? make effort to/ make efforts to 哪个对? make all effort 还是efforts? make one's effort to do sth to the best of one"s ability为什么要加to? take turns to do sth 这个句型里“turn”为什么要加S啊? Make every effort to do everything Make sb.do sth.为什么含make的句型,do前面不加to?类似的句型还有哪些?