cheerleader

The first one, because -- actually, I'm not quite sure how to explain it. Well, a quick search on google for "thing after thing was" has about 100 results, while "thing after thing were" has none.

Hmm. As I understand it, the only way to form a plural subject out of two singular nouns is to join them with the word "and". Other joining words like "or" require a singular verb, and I guess "after" does, too. There's probably a word for this sort of "one after another" construction -- does anyone know?

Cheerleader after cheerleader was practicing her move.

Though it does not have the same meaning it does have the same structure as

(A)cheerleader was practicing her move after (another) cheerleader.

or

After (a) cheerleader, (another) cheerleader was practicing her move.

You can understand after cheerleader as a group of words having a function of an adverb. Precisely with plural you can write only this way

They were practicing their move, cheerleader after cheerleader.

or

Cheerleader after cheerleader, they were practicing their move.

In this case, a complete expression cheerleader after cheerleader has an adverbial function: (each) cheerleader (in a group) after (each) cheerleader (in a group)

In English there must be a subject in the sentence, and there is no word to be a subject in

Cheerleader after cheerleader was practicing her move.

except cheerleader. And that gives us no right to use plural. Another example:

[Who] An apple [what] was cut. [Who] An apple [when] after an apple [what]was cut. [Who] They [what] were cut [how] (an) apple by (an) apple ((an) apple after (an) apple).

So two (third is only an inversion) options

• Cheerleader [when:] after cheerleader is/was ...
• They are/were ... ,[how:] cheerleader after cheerleader.
• [how:]Cheerleader after cheerleader, they are/were...

Interesting. I wonder if there's an official word on this anywhere.

Well, no matter, I guess; this doesn't come up too often.

Since the phrase "after cheerleader" is a prepostional phrase, the simple sentence should be "Cheerleader was practicing her move." and NOT "Cheerleader were practicing their moves."

Two things- Does each cheerleader only have one move? The way you stated your first sentece made it seem that way. Also, I believe the word you're trying to use is "practicing" NOT "practing"

"Cheerleader after cheerleader was practicing her moves." Should be right.