Focus on the pronunciation of furthest
English definition of “furthest”
/ˈfɜr·ðəst/ adj, adv (DISTANCE)
› superlative offar : The furthest west I’ve ever gotten is the Grand Canyon. Note: Both furthest and farthest are used as adverbs and adjectives. Farthest is more commonly used when referring to distances. Furthest is more often used when the intended meaning is figurative.