The way you said that is grammatically correct if that's what you were asking.
IS
'Business' in French is 'affaires'.
No, use "is" instead.
You can say that a business letter is effective when you get the response (result) that you desired.
"The business of America is business."
You can say "We are closed" to indicate that the business or establishment is no longer open for business.
A business plan is an outline for your business. The executive summary is the section of a strategic business plan that the U.S. Business Administration say is the most important part of the plan.
say that you are having your period.
"Thank you for your business" works quite well.
what does it mean to be unusually successful in business
"Oy vey, mind your own business."
I would say no because on their site they do not say anywhere on their homepage anything about small business, nor is there an easy access link to more info about it. There are several banks that specialize in small business and ones that do say so on their homepage or have a link on their homepage.