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.

a short presentation:

Hello everybody,
I'm happy to have come across this website, which is more or less what i've been looking for for ages. My interest for English started even before I entered the college (actually The equivalent of form 1 after 6 years in the primary school). My elder brothers used to speak in English whenever they wanted to hide anything to from us children. When I finally passed the common entrance exam, I was excited to about the fact that I would soon start my first English class. During the first year I did pretty well at English and could understand the basics.   My brothers had to think twice and used selected words to keep me out of their conversations.
Since that time I had only one goal: become proficient in English. Although it looks tough to achieve, I keep on struggling.

Looking forward to your corrections. Thanks