请问"曾参与过新同事的技能培训工作"用英语怎么说啊?

I used to participate in training new recruitment.

如果你是被培训的人
I have taken part in the new staff training programme.
如果你是培训别人的人
I helped with the new staff training programme

I have taken part in the training programm for the new colleague.

“参与”用undertake，“新同事”应该是“新员工”吧
I have undertaken the training course for new employee.