Forth and Farther

Forth adverb - Toward a point ahead in space or time.

Farther and forth are semantically related in ahead topic. In some cases you can use "Farther" instead an adverb "Forth", when it comes to topics like forwards.

Farther adverb - At or to a greater distance or more advanced point.

Forth and farther are semantically related in ahead topic. Sometimes you can use "Forth" instead an adverb "Farther", if it concerns topics such as forwards.