The /j/ sound is spelled with <y>, <ew> in ewe and is heard in the letter name U. The /w/ sound is spelled with <w> or <wh>.
This is a contrast between two semivowels, both voiced but well separated in the mouth the mouth. It only ocurs initially. In spite of the similarity, it is not a problem.
One taboo word pair is yank/wank.
The mean density value is 1.6%. The lists make 37 semantic distinctions, a loading of 57%.
ewe woo ewes woos ewer wooer ewers wooers U woo U's woos yacht watt yachts watts yacht what yak whack yaks whacks yaks wax yank wank yanked wanked yanking wanking yanks wanks Yate wait yaw war yaws wars yawed warred yaw wore yawed ward yawl wall yawls walls yawn warn yawned warned yawning warning yawns warns ye we yea way yeas ways yea weigh yeas weighs year were year whirr years whirrs yearling whirling yell well yelling welling yells wells yelled welled yelled weld yelp whelp yelped whelped yelping whelping yelps whelps yen wen yens wens yenned wend yet wet yield wield yielded wielded yielding wielding yields wealds yippee whippy yoke woke yon wan yonder wander yore war yore wore York walk you woo your war yours wars your wore
John Higgins, Shaftesbury, December 2010.