When referring to a group of people or things, is it correct to say
"That is they" or That is them"?  For example, I am waiting for my
parents to pick me up at the mall.  I see their car pulling up and say
"That is them".

I ask since the people or things would be the subject of the sentence,
which could mean that it is correct to use "they" rather than "them"
(e.g., it is correct to say "It is I" rather than "It is me".)

Hello -


I think that whilst the most common of the two phrases would be "that
is them" that is technically incorrect as this sort of sentence
requires the nominative rather than the objective case for the noun,
such that "that this they" is proper.

Dictionary.com lists the informal usage of them, as in "it's them"
which would suggest "that is them"
http://dictionary.reference.com/search?q=them

However, it also notes that formal English grammer requires the
nominative form of the pronoun in the predicate of the verb be: so
that the proper grammer would be "that is they".  However, it is also
noted that this rule is rarely followed by most speakers of the
language.
http://dictionary.reference.com/search?q=be

The Grammer Slammer also agrees that "it is they" is proper, although
rarely followed (section heading Pronouns in the Predicate Nominative)
http://englishplus.com/grammar/00000021.htm

Another grammer site suggests the proper pronomial use would be "that
is they":
http://www.engl.niu.edu/dhardy/grammarbook/program6/index.html


Please feel free to ask if you have further questions.

synarchy

Google: "it is them" grammer

Hi Koliver-ga.. The correct way is to say " There they are" . Any
other arrangement is not valid. Or " they are here". Or " here they
come". I am not sure where you live, but I suspect its the good old
U.S. OF A. I`M SORRY, BUT THE YANKS REALLY DO BUTCHER THE ENGLISH
LANGUAGE.

Actually, the verb "to be" does not always require the nominative
case. The appropriate rule is that, as a copulative verb, "to be"
should link two noun phrases of the same case, be it nominative or
accusative. Hence: "I believe that he is I"; but also: "I believe him
to be me".

This still implies that one should say "it is they" - just as one says
"who are they?" and "it is they who are at fault". In practice,
however, this is often viewed as over-correct. I'd recommend sticking
to "it's them"...

Source: http://alt-usage-english.org/excerpts/fxitsmev.html

Pugwashjw-ga,

I note several grammatical errors in your comment - several sentence
fragments, one unclear participle, and one incorrect conjunction (it's
not its)...

Were these merely learning points from an esteemed British
grammatician?

Wow! I never heard of a "copulative verb" before. Thank you, uriel-ga.

But as for synarchy-ga's reference to a "grammatician", would that be
something like a mortician for grammar?  (Just kidding!)