是they usually go to the shop and help their mother to do some shopping对还是they usually go to the shop and help their mother does some shopping对?

问题描述:

是they usually go to the shop and help their mother to do some shopping对还是they usually go to the shop and help their mother does some shopping对?

第一个吧。

help sb (to) do所以第一句可以算对

the first is right
help sb to do sth
而且their mother不是单数 why use does?