"He will walk in the park this afternoon."

Translation: Ele vai caminhar no parque esta tarde.

[Elen-ka]

"passear" should be acceptable also

[andoreh]

Yes!

[RogerW.]

Would someone like to explain the differences between "andar" and "caminhar"?

[GregoryFie10]

Esta tarde, ele vai caminhar no parque.
Not accepted, but I know it isn't wrong.

[Paulenrique]

Also right.