Use of was/were in this sentence

[QuicksandBug]

Hello teachers,

I'm having a minor trouble with the use of was/were on a specific sentence, I've been using Grammarly and a few other grammar checking tools to make sure I'm not making silly mistakes, but I'm not getting a clear answer for this one.

Multiple framed blank canvas were hanging on the entirety of the hallway's walls.

The corrected version on one of the tools came as the following, "The multiple framed blank canvas was hanging on the entirety of the hallway's walls."

Now seeing this just bugs me, and I just wanted to make sure.

 

[emsr2d2]

I imagine that the problem is being caused by the fact that you start with "Multiple" but then use "canvas" instead of "canvases". If there were multiple, you need the plural noun.

 

[tedmc]

Canvas could mean the material or a piece of painting, so it is multiple-framed canvases.

 

[emsr2d2]

Canvas could mean the material or a piece of painting, so it is multiple-framed canvases.

The hyphenated adjective "multiple-framed" isn't right. There are several canvases and they are all in frames, so it's simply "Multiple framed canvases ...".