There is no English word "Alis". The phrase that you are thinking of is: "I'll cure what ails you". That phrase means that the person will solve your problem. "Ails" refers to a sickness or something that disturbs someone. Even more broadly it means a negative influence. The phrase is not always used for literal sickness. It is commonly used to refer to emotional problems. EDIT: I realise I made a mistake. You said "It'll cure what ails you", not "I'll cure what ails you". The same applies except that it is a thing that will solve your problem, not s person.