Can one copy a pattern for resale IF...?

I tweak it and not word for word and add a different style and word it differently? is that ok to sell? I have lots of patterns but others have made the exact item and they all are just worded in their own words, just basic and simple. i would never sell a pattern of someone else or co and add my name of course... but for example a shopping car cover or a dress can be the same thing someone else has designed. so.... I can see if you tweaked it, by using your own words and pattern... is this what I see or am i the only one? lol