I have read sources from the internet claiming that Iago in Shakespeare's play; Othello has 1097 lines yet I have also read that Iago has 272 lines. Which is it? Here are the links to the individual websites:
The only thing I could suggest is, in the first one, 'lines' refers to the number of times a character speaks, regardless of how many actual lines of verse/prose are spoken within each speech, whereas the second figure refers to the actual number of lines on the page the character speaks.
robbo is probably right, the one mistake people studying shakespeare make is that you are reading a play, not a book, and you have to have a sense of the stage when reading it. (actually there are loads more than one mistake I guess)
I studied this play for my A-levels (some time ago) and from what I remember, Iago had more spoken lines than Othello even though Othello is the main character/tragic hero of the play.
The fact that Iago is given more lines than the central character makes him much more of a 'mystery' character and casts doubt over his real role, motivation and importance in this play (as well as Shakespeare's intentions w.r.t. Iago's character).
Despite Iago having more lines, the most powerful and poetic lines/soliloquies (sp?) are reserved for the sensitive Othello which reinstate his role as a tragic hero, so it all balances out in the end.