plurals

[bartholomew]

� All children will have parents' and teachers' Connor's questionnaires completed.

or

� All children will have parents and teachers' Connor's questionnaires completed

[Quizmonkey]

The first is grammatically correct - I can't see how the second can be right in any context.

[Loosehead]

The first one says that the Connor's questionnaires that apply to teachers and the Connor's questionnaires that apply to parents will be completed as applicable to each child.

The second one says that the Connor's questionnaires that apply to teachers will be completed as applicable to each child and that the parents will be completed (construction thereof presumably!)

[Quizmonster]

As I've never hear of it, I wonder whether the Connor(s) element requires an apostrophe at all. Presumably it is the name of the person who designed the questionnaire and that might be 'Connor' or 'Connors', both recognised surnames.
Usually, as in 'Heimlich manoeuvre' or 'Bessemer process' the straightforward surname is used in such circumstances, with no possessive apostrophe. Thus, we might have either "Connor questionnaires" or "Connors questionnaires".
Assuming that parents and teachers all have to complete these, then both these words should indeed have an apostrophe after the 's'.

[Peter Pedant]

In english "and" must connect two identical grammatical phrases.

so they both have to be one or the other.

and a c questionnaires that belongs to both parents and teachers is ....number one