hi sharath, it seems everyone ignore ur problem, right? i've seen ur post a few days ago, but i don't reply 'coz i'm not sure with them as well. but now i'll try my best to clear ur doubt
Here are my suggestion:
1- would and could can have many uses but i think they mostly appear in polite request or offer
eg. Would u like a cup of coffe?
offereg. Could u pass that book for me?
request2- could can be past tense of can and it's more polite than can.
Yes, would and could can be past tense of will and can.
i think you can use them whenever u want but i suggest you should use would and could if u wanna be polite, esp. when u need help!
i think grammar books will help u more so why don't u consult them :?:
that's all for me !
i hope ur doubt will be afraid of u one day! :!: any suggestion with this doubt just share now!hope to be the best one day
jupiter