Q: Can "as well as" be used without commas before and after the phrase and does it require a singular or plural verb?
“John as well as Raju are involved in this project.” Is this correct?
The phrase "as well as" means in "addition to" or "and also" in the context of the example that you have mentioned. When "as well as" is used as a conjunction (i.e. in place of “and”), there is no need to use commas before or after the phrase. Moreover, it should always be used with a singular verb.
Therefore, in your example, the correct way of writing is "John as well as Raju is involved in this project."