I'm quite confuse with the auxiliaries "Can, Could, May, and others you can named it". I will list a few examples. Could you do me a favor? Can you do me a favor? May I go back home early today? Can I go back home

(1) I did not played with him yesterday. I did not play with him yesterday. I did played with him yesterday. I did play with him yesterday.

Sorry, I still don't understand, would you mind to give some examples?

Clive wrote: It asks about how much these methods can be used by companies that are having difficulty surviving. Can I write about the advantages and disadvantages of the "classical approaches" ? Are they related?

I'm doing an assignment, the question as below, To what extent classical approach can be adopted by organization for their business survival. Thanks for replying

Marius Hancu wrote: Both are correct depending on context. Student's grievances means e.g. John's grievences. Student grievances are grievences issued by all students Why can't it be students grievances instead of student

As title, I'm confused and don't know which one is correct. Thanks for replying.

what are their differences?

What are their differences? Is it besides this, or beside this?

Thanks for your help! Can I ask something not related to grammar? How do I say a company that is practicing e-commerce? Sorry for my poor English, I just want the correct sentence. Nowadays, most of the companies/company are practicing e-commerce?