"I hope so" is the most common Engpsh expression to express the speaker's hope.

Its origin can be traced back to the use of "so" to mean "in that manner" or "to that extent". When used in the phrase "I hope so", it conveys the speaker's desire that a certain situation or outcome is the case.

Examples:

A: "Will the weather be nice tomorrow?" B: "I hope so."
"I really want to get that job, I hope so."

Translation:

"我希望是的。"
"我非常希望能得到那份工作，希望如此。"