as that of

[youandcorey]

Please vote on which one you think is correct.

Thank you.

1. He was as childish as a young kid.
2. His behavior was as childish as that of a young kid's.
3. The temperature of Hawaii was as warm as that of California.
4. The temperature of Hawaii was as warm as California's.

[Raymott]

Please vote on which one you think is correct.

Thank you.

1. He was as childish as a young kid.
2. His behavior was as childish as that of a young kid's.
3. The temperature of Hawaii was as warm as that of California.
4. The temperature of Hawaii was as warm as California's.

I like 1 and 3.

[5jj]

2. His behavior was as childish as that of a young kid's.
4. The temperature of Hawaii was as warm as California's.

I also like #1 and #3. I think #2 is also OK; #4 is not wrong, but would be better if it began 'Hawaii's temperature ...', in my opinion.