When they walking into the hall,they fall asleep.这句话从语法上看对吗

问题描述:

When they walking into the hall,they fall asleep.这句话从语法上看对吗

有错!句子中都有主谓宾等等构成,而该句却漏了谓语,应该这样子:When they are walking into the hall,they fall asleep!