Need help figuring if my work experience is eligible for express entry

[Newgirllabel]

I have a masters in biotechnology and work for an mnc with a work exp of 2.5 years which is going to be my primary occupation and noc while applying for express entry. Before joining my current workplace, I worked for a private coaching classes as an exam paper evaluator ( paper correction for std 8th-10th) and giving feedback to students about how they could improve their scores. I did it for a period of 1 year. I was paid in cash. Can this paper correction work experience be used under NOC 4021 as other skilled experience to apply for express entry? Kindly provide your expertise.

 

[Naturgrl]

You can include the work experience as long as you have the employment letter on company letterhead, signed, lists duties, time worked and salary.