Reading the article "How to Introduce People", I (not a native English speaker) found no rules for introducing of two (or more) people. Neither could I find links to the related posts here, on ELL.
Were it I to do the introduction, I'd say, for example:
..., this is Tom Smith, our business partner; and this is Jim Blake, our lawyer.
..., this is Mr. Smith, our business partner; and this is his wife Helen.
I am wondering, if it would be possible and not incorrect to make do without "and this is" here, saying:
..., this is Tom Smith— our business partner, and Jim Blake— our lawyer.
..., this is Mr. Blake--our lawyer, and his wife Helen.
..., this is Mr. and Mrs. Blake, their son Mike, and their daughter Jane.
Maybe I'm over thinking it, or maybe I missed something important, studying English grammar, but more than one and "is"… Well, I've never had the occasion to think about it until just now.
What really confuses me is what if I had to introduce, say, some of my friends to my father? Would it be possible (I myself doubt it, though) to say:
"Dad, this is Tom, Jack, and Sandy, my cronies"?
If it would, wouldn't it lead to:
"Dad, this is my classmates: Tom, Jack, and Sandy"?
(Which is rather confusing compared with "these are my classmates")
This question wasn't spun out of a thin air:
In the digital edition of Collins Cobuild English Usage (para 1.126), I have read that when introducing people, one can use this even when he is introducing more than one person:
"When you are introducing people, you can say 'This is Mary' or 'This is Mr and Mrs Baker'. Note that you use this even when you are introducing more than one person."*
(* Added on June 12)
Hard as I tried, I couldn't find any other source backing this statement.
In this regard, would it be correct to make introduction like these:
Mom, this is Jane's favorite pupils Pete, Jack, and Andrew.
Sir, this is the two men I've just told you about.
Would someone kindly help me clear that up?