On the relation between thought and words.

Sapir - Whorf hypothesis says that your ability think a thought depends on knowing the words that are capable of expressing the thought.
If you dont know the words, you cant express the thought and you might not be even able to formulate it.

- From Code Complete.

Thoughts on the hypothesis : The last part of this cannot be true, since words originate from people being able to express ideas that do not yet have words associated with it.