Pain and ache Gyus, explain me, please, what is difference between "pain" and "ache"? When we need to use "pain" and when "ache"? Thanks a lot!

Possessive and Double possessive Please, tell me what for there is possessive and double possessive in English language ? write several examples, please. Thanks!

Thoughts develop humans What do we know about thoughts? What power is it have? Due to our ability of thinking we have got that we have - technologies, knowledge, civilization. Someones have made a something more than other. Einstein, Mendeleev, Pythagoras and many of other peoples have made a major contribution in the develop of our civilization. But how did they do it? What process, what scheme of thinking did they use? All of the world is obeying some principles, algorithms and it isn't depend we know their or not... So maybe is there something algorithms to thinking so effective? Make the text correct, please (this sentence too) Thanks a lot!

My first note Hi to everybody from Kazakhstan! My name is Alibek and I'm 22 years old. I studied English at school from fifth grade and studied at college too, but for lack of practice and real need I forget almost all... Now I have a real need in English, because I want to get the ACCA qualification. It's important for for me, because my profession is an accountant. So I hope I can learn spoken English in the short time and go to the Business English courses. And only I have good English I'd go to the ACCA courses and pass its exams. I think it will have about 3-4 years for to get all ACCA's papers.