--> Corroborative has double "rr" is mispronounced as "r"
Remember double 'RR' in between the strings co & oborative which should not be misspelled with single 'R'
Wrong Spelling:  co-r-oborative 
Correct Spelling:  co-rr-oborative 
Find more incorrect spellings of Corroborative to spell right way.