The /Ɵ/ sound is spelled with <th>. The /w/ sound is spelled with <w> or <wh>.
This is a contrast between a voiceless dental and alveolar fricative and a voiced bilabial semivowel. It is not a problem.
There is one taboo word pair in thank/wank.
The mean density value is 1.5%. The list makes 21 semantic distinctions, a loading of 47%.
thane Wayne thane wain thanes wains thank wank thanked wanked thanking wanking thanks wanks thaw war thaws wars thawed ward theft weft thefts wefts theory weary theories wearies therm worm therms worms thick Wick thicket wicket thickets wickets thieve weave thieves weaves thieving weaving thigh Y thighs Y's thighs wise think wink thinking winking thinks winks third whirred third word thirds words thirst worst thirsted worsted thirsting worsting thirsts worsts thistle whistle thistles whistles thorm warn thorns warns thought wart thoughts warts thunder wonder thundered wondered thundering wondering thunders wonders
John Higgins, Shaftesbury, November 2010.