Dul or Dull: How To spell?
The word Dul is misspelled against Dull, a verb meaning "To become dull or stupid."
Dull has double 'll' in the end mispronounced as 'l'Remember double 'LL' appears in the end of this word which should not be misspelled with single 'L'
Wrong Spelling:  du-l  Correct Spelling:  du-ll 
Check more misspelled words of Dull to spell it correct.