a one-sentence summation of Sapir-Whorf isn't going to do you much good. here's a pretty good overview of Sapir-Whorf and the antithesis:
http://www.aber.ac.uk/media/Documents/short/whorf.html

to me, what's meant by "structure of a language" isn't grammar but more along the lines of patterns of interpretation. here's another statement one could debate: the Sapir-Whorf hypothesis advocates that language has the power to dictate man's world view in a tyrannical way.