Today I encountered a sentence:
"At night, we would lie on the porch in the sleeping bags my grandmother had bought, drink cocoa, and listen to the chorus of crickets"
Let take a look at the first part of this sentence:
"we would lie on the porch in the sleeping bags my grandmother had bought"
We can re-write without any change of meaning:
"we would lie on the porch in the sleeping bags which my grandmother had bought"
But I believe that the information "my grandmother had bought" is just additional information so it should be non-defining clause. I think this sentence should be written like this:
"we would lie on the porch in the sleeping bags, which my grandmother had bought"
Then I place this part in the first sentence then the sentence look weird to me:
"At night, we would lie on the porch in the sleeping bags, which my grandmother had bought, drink cocoa, and listen to the chorus of crickets"
Could someone please explain which part of this process is wrong.