Farther: Farther strictly expresses greater distances in time or space.
Further:Further is also used to describe something as additional or greater in degree.
Similarity BetweenFarther & Further
Farther and further as adjectives mean greater distance.
Both words are comparatives of ‘far’.
The birds flew to fartherfields in search of food.The birds flew to furtherfields in search of food.
Farther and further are also used as adverbs to indicate that an action was continued for a greater distance or extended.
The birds flew farther in search of food.The birds flew furtherin search of food.
In other words, when it comes to measuring physical distances, it doesn't really matter which word you use.
Farther vs Further
While farther strictly expresses greater distances in time or space, further can be used differently.
As an adjective, further is used to describe something as additional in degree too.
It can also be used as a verb to express the action of helping something to become successful or move forward in a symbolic sense.
The police will conductfurtherinvestigations on the case.If you require any further information, feel free to contact me.This new policy will further their political interests.If Kelly wants to furtherher education, she will need financial aid.
Time for Some Pro-Tips
If you can measure the distance physically, use either of the two. For everything else, further is the right way to go!
Check if you can replace further in a sentence with “additional” or “more.” If yes, you are using it correctly.