Is it proper English to say:" All you need are Rita, George and a Schnauzer"? [duplicate]

I carved a sign and my wife says that the message does not sound grammatically correct. Can you help?

Solution 1:

The verb should agree with the subject. All can take a singular or plural agreement, depending on what all refers to:

All the pizza was eaten.
The thing that was eaten was the pizza.
All was eaten.

All the slices were eaten.
The things that were eaten were the slices.
All were eaten.

Similarly, both is and are work here:

All the company you need is Rita, George . . . and a Schnauzer.
The thing you need is Rita, George . . . and a Schnauzer.
All you need is Rita, George . . . and a Schnauzer.

All the companions you need are Rita, George . . . and a Schnauzer.
The things you need are Rita, George . . . and a Schnauzer.
All you need are Rita, George . . . and a Schnauzer.

As the article When the complement was roses attests, agreement is often an art—not a science.