Wow, this a tough question. To be honest each pair of words mean exactly the same thing. All of them are adjectives. Native English speakers have debated the differences between the different forms of these words for as long as they have been around. The general consensus is: the difference is a matter of style. The difference is so minuscule, most native speakers wont be able to tell you the difference. I do remember being told at school: if in doubt use the shorter form