hi, i just want to ask on how to stretch hatch patterns? thanks...

Double click on the hatch pattern.  This should bring up the hatch edit dialog box.  Pick on Recreate Boundry, hit enter 3 times (read the command line so you will know whats happing). Now click on the hatch boundry and you'll notice you have pick boxes in the corners.  Stretch all you want.
To get rid of the boundry, pick on it and erase it.

thank you very much, i have stretched the boundary... Also, what about the hatch pattern? Ex. Making a rectangle, then hatch it with brick. When the rectangle was stretched so that its vertical lines appear leaning, is there a way also so that the hatch's vertical lines also would appear leaning?  I have tried selecting an angle inside the hatch command but it rotates the pattern, not making the vertical lines lean.

You have created the boundry with lines.  When you do this you must pick the end of each of the lines, in other words pick both lines then pick the pick box at the end of the line, then stretch.  Hope this fixes your problem.

what about using associative hatch so that if you stretch an object, the hatch is being stretched with it ..

Be careful with associative hatch, sometimes they behave quaintly or causes some problems, especially complicated form of solid hatch.