[Grammar] Those with college or university education can earn a higher salary.

[yi-ing]

Could anyone please tell me in a short explanation what the differences among these are?

Those with college or university education can earn a higher salary.

Those with college or university education may earn a higher salary.

Those with college or university education could earn a higher salary.

Those with college or university education will earn a higher salary.

 

[yi-ing]

It is possible that they will do or will earn a higher salary.

Thanks Piscean. It was really helpful.

So, why did you use will do as well as will earn?Can we say "I will do a higher salary"?