Q:

Correct grammar: 沒有把你照顧好 vs 沒有好好照顧你?

Someone said the following in Mandarin to express not taking good care of you: 沒有把你照顧好.
In Cantonese, it seems more natural to drop 把 and say something like 沒有好好照顧你.

What's the correct grammar?
Are Cantonese and Mandarin grammar different for this phrase?

A:

Both are correct and natural in Mandarin, but have slightly different meanings.
沒有把你照顾好 is equivalent to 没有照顾好你, which means "the result is not good", while 没有好好照顾你 means "the effort is not enough". 

A:

As @JasonSwift said, both are valid in Mandarin. The difference is between 照顾好 and 好(好)照顾. The first 好 is a "result complement", the second two - simply an adjective. With 没有 it's more of "the caring taken didn't have a good result" vs. "the caring taken itself was not good".

