Grammar police question?

The second one

“He kept thinking about his and Liz’s philosophical question.” Is correct.

“He kept thinking about Liz’s and his philosophical question.”

Is another option-it does seem a bit awkward to me though.

He kept thinking about his and Liz’ philosophical question

The first answerer is partly right. However, the other person in the sentence should be named first. So it should say:

“He kept thinking about Liz’s and his philosophical question.”

The 2nd one..

It needs to be able to stand on its own..take out the ‘and Liz’

He kept thinking about his philosophical question

I’m sure there’s a better way to word it

“He kept thinking about his and Liz’ philosophical question”. Is the right one.

Neither

“He kept thinking about his and Liz’s philosophical question”.

I don’t think any of them are correct, since not only does the sentence lack a sense of elegance when spoken? It also doesn’t seem to focus on its true subject very well.

The focus of this sentence isn’t on “He and Liz” but rather the “philosophical question”. Perhaps it’d be better to kill two birds with one stone and rewrite the line as:

“The philopsophical question that Liz and he shared just wouldn’t get out of ‘s mind.”

Or something to that effect. Direct, to the point, and reads aloud far better. When in doubt, sound it out, and always try to keep the core subject of your sentence clear.

I think it should be,

“He was thinking about the philosophical question he and Liz asked”.

“He kept thinking about his and Lizs’ philosophical question.” would be correct if they have the same question. If they each have a question, it would be “He kept thinking about his and Liz’s philosphical questions.”

“He kept thinking about he and Liz’ philosophical question”