Mr.Smith takes walks in the park.

首先这个短语应该是take a walk
Mr.Smith takes a walk in the park.这句话语法上来说是正确的.
但是句子用一般现在时有点别扭.一般是不会这样说的.
我觉得用一般现在时的话加上like/enjoy doing/would like to do..等等（例：mr.smith likes taking a walking in the park）会更好
或者用现在进行时,mr.smith is taking a walk in the park.这种要看情况