en_tn/job/38/18.md

Have you understood the earth in its expanse?

This can be expressed as a statement. Alternate translation: "You do not understand the earth in its expanse." (See: rc://en/ta/man/translate/figs-rquestion)

the earth in its expanse

"the great broad places of the earth"

if you know it all

"if you know all about these things"