请告诉下what引导名词性从句的做成份问题。

一直弄不清楚比如Do you happen to know what size shoes he wears?中 what 充当从句的什么语?还有We gave him what help we could.what 的位置用that 可以吗?what充当什么语?谁能帮忙分析下。我的what that一般都能分得清填什么。但是到上面那种句子里就觉得填that 谁可以指导下。谢谢

Do you happen to know what size shoes he wears?还有We gave him what help we could.what引出宾语从句,又在从句中充当一定成分,表示疑问,什么,这时候只能用what而不能用that,that只用于引出宾语从句并不在从句中充当成分
温馨提示:答案为网友推荐,仅供参考