My MacBook will not let me move files to the trash.

I have a 2007 MacBook. Mac OS X 10.6.8

When I try to move a file to the trash I get the following message: "This item will be deleted immediately. You can’t undo this action."

This is very new, it just started happening a few weeks ago for no apparent reason.

In Terminal I got the following:

Angela:~ angelacookson$ ls ~/.trash

ls: .trash: Permission denied

How do I get "permission" to use my trash??

As well, when I last tried to back up my MacBook using Time Machine paired with an external harddrive, my MacBook does not recognise the device & wont do the back up... I can't help but wonder if this is connected...

Thank you!