Suggestioned welcomed is incorrect english - ed is past tense so aap kehna chahte ho suggestions welcome kiye the.. Suggestions are welcome is the correct phraseology
Ok will try to answer which & what ...
1) aap which ko what se replace kar sakte ho and be grammatically correct but what ki jagah use nahi kar sakte
2) which appropriately use ho hai where choices r limited ... for eg - which of u moderators deleted my post .. which route to take to go to mohali, which CD to buy... jahan 2-3 option ho basically ..
safest hai dont use which :P
U can give me sentences and I can tell you where which/what fits...
Mate, I'm working on this software is the correct answer ... of course u can say both together..
if some1 asks me whats up i wud say hey, nothin much, in bed, whats up wid u..
whats up what u upto is basically whats happening with u...
Yes, you're right both are same but this was real incident happened with me ages ago. Earlier, I guessed it can be different to other people from country to country. I shall put some more soon.