Re: He gives training for the new staff. (Can we say give training?).
1. You can say "give training" but it's followed by "to", not "for". It's better worded as "He trains the new staff" though.
Originally Posted by Jit833
2. I assume you meant "the employer" at the beginning. I would write it as:
"The employer and one of his employees failed to properly discuss the employee's work schedule. Both parties were confused and that is why the employee failed to arrive for work when he should have."
Remember - correct capitalisation, punctuation and spacing make posts much easier to read.