Juan likes to take a different route from his house to school every day of the week. Sometimes he follows the sidewalks all the way to school. Sometimes he takes a shortcut through the park. Sometimes he zigzags, looking at interesting plants and bugs as he walks. What is always the same about Juan's route to school?

The one thing about Juan's route to school that is always the same is his walk.

Explanation:

Juan takes different routes when going to school. Sometimes, he would walk along the sidewalk, at times take a shortcut through the park, zigzagging along the way and observing the plants and bugs along the way. These paths may differ for Juan as he makes his way to school.

But the thing that is always the same about his route to school is his walk. There is no mention of Juan ever riding a school bus or being taken to school by any vehicle for that matter.

Thus, his walk is always the same about his route to school.

noun : part of speech

verb : variation