if you have a min of 1 year exp in CANADA either in NOC O,A,B.... and have previous years t4, NOA, req IELTS band, You would be eligible Under Canadian Experience Class
you have to prove that you are legally to work in canada to gain your work experience. To prove you had work experience before, you should provide your working income T4 forms and NOA which you received from CRA after you do your personal tax return and also you need to demonstrate your english is good which means you need to take an english test. even you are from USA or UK, you still need to take the test.