Spell check is effective, especially, when you are working on official things, like work documents, school papers, important mails etc. People usually make mistakes while typing which they do not notice. Spell check fixes our mistakes.
Spell check will not detect the improper use of homonyms, such as "their" and "there." Spell check may flag words as errors which are indeed correct. Spell check does not always offer useful spelling suggestions for severely misspelled words.
Oftenly misspelled words:
beginning (as begining)
embarrass (as embarass)
business (as buisness)
separate (as seperate)
government (as goverment)
