1.ask about sth (sb) 询问有关某人或某事的情况.如：
She asked about his health.她询问他的健康状况.
Can I ask about the exam results?我可以问问考试结果吗?
2.ask after sb 问候某人(的健康).如：
They all ask after you.他们都问候你(的健康).
3.ask for sth 要求得到某物或要求与某人见面.如：
He asked for some water.他要些水.
A Mr Smith is asking for the manager.一位名叫史密斯先生的人要找经理.
4.ask sb for sth向某人要某物或请某人给某物.如：
They asked me for help.
He asked her for her address.他向她要她的地址.
5.ask to do sth要求或请求做某事.如：
He asked to see the manager.他求见经理.
He asked to see whoever was in charge.他要求见负责人.
He asked to go alone.他要求一个人去.
6.ask sb to do sth 请或叫某人做某事.如
Ask John to mail these letters tomorrow.叫约翰明天把这几封们寄了.
He asked us to wait for him at the gate.他叫我们在门口等他.
大概就这么多吧
