Earlier quoted context omitted.
> I tend to try something on with employment contracts too - I return an unsigned copy to the company. So you email it back without comment, which shows you received it and understood what it was, and then started work… I suspect that’s binding in many jurisdictions, and the lack of an actual signature is simply an inconvenience
What if they crossed out a few clauses and signed, and the employer never noticed. Are you saying that because they begin working for the company, that represents the company's tacit acceptance of the modifications to the contract?
There’ll be explicit case law but it’ll come down to “would a reasonable person think the changes to the contract had been accepted”