Hi,
IRCC says;
"Can I count my work as a teaching assistant toward the work experience requirement?
You
may be able to count experience as a teaching, research or lab assistant at a post-secondary educational institution, (see
National Occupation Classification 4012) toward the work experience requirement, depending on the eligibility criteria of the programs.
If after submitting your Express Entry profile you are invited to apply, you must show that you did the job as described in the occupational description of the NOC, meaning that you did all the essential duties and most of the main duties listed. If you do not show that your experience meets the description in NOC, your application will be refused.
To be considered under the Canadian Experience Class:
You cannot count work experience you gained while enrolled as a full-time student. Your work experience must have been gained while on a valid work permit, such as the
Post-Graduation Work Permit.
You must have gained the equivalent amount of experience as someone who worked full-time for at least one year (1,560 hours) in the three years before you submit your Express Entry profile.
To be considered under the Federal Skilled Worker Program:
Your work experience must have been full-time (or the equivalent in part-time hours), worked continuously and paid, for at least one year in the same occupation."