1) You need the word 'for,' after working and before seven. 2) If somebody offers a proper price. 3) This is grammatically correct BUT we would normally say that our hair is wet, rather than our head.

They are all understandable, and grammatically correct more or less. You've done a lot of work to get to where you are! As a native speaker, I notice these sentences sound very formal. That's ok in some contexts, but for conversation I'd make some changes. 1 After working seven years at Uzbekistan Airways, I'll be given a free air ticket a year. WITH the free air ticket I'll be able to travel around the world for free. 2 I'll sell my house if somebody offerS a GOOD price. 3 My head is wet BECAUSE I went home in the rain.

1 After working seven years at the Uzbekistan Airways, I'll be given a free AIRLINE ticket a year. Thanks to the free ticket I'll be able to travel around the world for free. 2 I'll sell my house if somebody offers a GOOD price. 3 My head is wet BECAUSE I went home in the rain.