Enterprise/enterprises

An enterprise is a company or business often a small one.
This was the definition of enterprise.

My question is, some people use enterprise and some use enterprises. What is the right way of using “enterprise”
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David enterprise or
David enterprises.

Thank you.

In a company name, ‘enterprises’ is normally used… but there is no hard and fast rule about that. It depends on the individual circumstances.

Thank you.

I have another thing to ask.

I have been waiting for you since yesterday.

Can I say the same sentence in this way?

I waited for you since yesterday.

What would be the difference in both the sentences and are both of these sentences correct?

Thank you.

‘I waited for you since yesterday’ does not work. It would have to be ‘I have waited for you since yesterday’

There is no significant difference between ‘I have waited’ and ‘I have been waiting’ here.