to tell u the truth , there may be diffenrent meaning in just one word ,polysemy is a common phenomenon in different languages . 我对罗兰说means i said to Rowland . 对is a prep. it can also be a adj when it means "sth /sb'ideas or decisions is right " like是

frankly,there is no difference between these three sentences , and all of them is nature . but all its meaning may hurt the listener , u d better be more mild and roundabout .