the crowd is on the edge(s) of their seat(s)

What is correct?

The crowd is on the edge of their seat.
The crowd is on the edge of their seats.
The crowd is on the edges of their seat.
The crowd is on the edges of their seats.

and

The spectators are on the edge of their seat.
The spectators are on the edge of their seats.
The spectators are on the edges of their seat.
The spectators are on the edges of their seats.

Thanks

Anyone?

• I would say "The crowd are on the edge of their seats."

Not "The crowd is...", as "crowd" is usually considered to be a plural (it is made up of more than one person), so is treated as such. Except, I believe, in America they would tend to treat "the crowd" as a single entity... but I'm not sure which one of the four they would consider as correct.

• I would say "The spectators are on the edge of their seats."

"The spectators" each have their own "seats", not one single seat amongst themselves. However, each spectator is only "on" one "edge" of their seat, they're not "on" multiple edges of their seat. Well that's my reasoning anyway.

In the first one, "their" is technically not the correct word to use. Since "crowd" is singular, you would have to said, "The crowd is on the edge of its seat," or something.

However, I think that what you would be most likely to hear is "The crowd is on the edge of their seats."

Technically, in English, it should be "edges of seats", but you will often hear people leave off the first plural and sometimes the second one.

You might hear "The spectators are on the edges of their seats," or "The spectators are on the edge of their seats."