;WITH ConfuseWords AS(
SELECT 'hi' AS [word_text],'meet' AS [relatedWord_Text], 1 as [LevelNo], 1 as [UnitNo]
UNION all
SELECT 'meet' as [word_text],'hi' AS [relatedWord_Text], 1 as [LevelNo], 1 as [UnitNo]
UNION all
SELECT 'he' as [word_text],'his' as [relatedWord_Text], 1 as [LevelNo], 3 as [UnitNo]
UNION all
SELECT 'his' as [word_text],'he' as [relatedWord_Text], 1 as [LevelNo], 3 as [UnitNo] 
union all
SELECT 'table' as [word_text],'coffee table' as [relatedWord_Text], 1 as [LevelNo], 3 as [UnitNo] 
)
,
cte as
(
    select row_number() over(order by word_text,relatedWord_Text) rn,* from ConfuseWords
)

select word_text,relatedWord_Text, LevelNo, UnitNo from cte t
where exists(select 1 from cte where t.word_text=relatedWord_Text and rn>t.rn)
/*
word_text relatedWord_Text LevelNo     UnitNo
--------- ---------------- ----------- -----------
he        his              1           3
hi        meet             1           1
*/