The simple answer is probably 'both'. A fascinating question, though. All depends where you stand on the Sapir Whorf hypothesis, I guess. Most of us know about the 'Russian blue' experiments, which suggested that our native-language vocabulary system may impact on the neural processes of the brain. 

Another area that interests me is whether the concept behind continuous aspect affects how you see the world. In one experiment, German speakers, English speakers, and bilinguals were asked to describe certain pictures. When faced with a photo of a woman on a bike, the English speakers all  said "The woman is cycling" or "The woman is riding a bike". Meanwhile, the German speakers described the same picture by saying that the woman was on her way to a supermarket or her office, for example. The German language has no continuous aspect (indicating just the activity taking place at the moment) so the German speakers focused more on the purpose of the activity. This could suggest that a lack of continuous aspect makes speakers more goal-orientated than those whose languages give them the option of focusing on the process rather than the outcome.

It would be  interesting  to hear comments from speakers of other languages which don't distinguish between "She rides" and "She is riding", particularly if you are now fluent in English or another language which does have a continous aspect.  For example, if your language doesn't have a continuous aspect, did you find that you started looking at things differently in order to decide whether to use a simple or continuous verb form in English?

Thank you, Alessio, for starting a really  worthwhile discussion. As many people have pointed out, we are short of genuine discussions on these pages!

What you're asking about is if the Sapir-Whorf hypothesis is true. In nearly a century, this hypothesis has failed to be proven in even its weakest form. If that's not a definitive "NO" I don't know what is. We have more evidence that mermaids exist than we do in proving the Sapir-Whorf hypothesis.

It's a fun idea. A romantic idea. But there isn't the slightest shred of evidence to prove it. Sorry to piss on the parade. :(

However, while it may fail to shed any light on the impact of language on our thoughts, the Sapir-Whorf hypothesis *is* good at creating urban myths. (see: Hopi time controversy)

Su Ki - I agree with most of what you've said. However, I do find the results of this study with the woman riding a bike extremely puzzling. Perhaps there was some sort of misunderstanding or mistake in the wording of the task or something?  Because it's perfectly possible to clearly indicate that an activity is happening right now (or was happening at some previous point in time) in German. And we do use it, too. If you called me and wanted to know what I was doing (in German), you'd simply say "Was machst Du (jetzt) gerade?". And this is, to all intents and purposes, the exact equivalent of "What are you doing (right now)?" Which rather renders the question obsolete of whether or not Germans have a different perception of time, just because their verbs lack the continuous form, doesn't it?

Apart from that, I strongly disagree with the notion that language shapes our consciousness. And I don't think that the fact of whether or not a particular language has a word for a particular colour proves me wrong. Just as a seaman might have 20 different words for clouds, wind or waves, a gardener will have many more words for flowers or trees and a painter for colours, and if you lived in Alaska, you'd differentiate between several kinds of snow and ice. But, as far as I can see, if - in whatever language - you try to forcibly replace word X (perceived as derogatory) with Y (up to this point perceived as neutral), then the only thing that's going to happen is that Y will become derogatory. The only positive side effect being that simply by discussing words X and Y, a few people MIGHT become aware of the fact that they had hitherto had unfair prejudices against X.

That is an interesting topic but a tough one for me to say how the language I speak shapes my thoughts! But still, let me try:) 

We all know that language is a tool to express our emotion and thoughts and it often gets influenced by our culture and geography. And our culture and environment have an influence on our thoughts as well as on the language we speak but I can't think of any logic that how the language we speak can mold our thoughts. What Su.Ki. mentioned was interesting but Is that something to do with the language they speak or the culture or society they live in? For example, the German speaker said that the woman was on her way to a supermarket or her office. He might have said that because he was aware of the fact that most of the women who live in his society used a bike in order to go to the office or a supermarket. So the more frequent picture of a woman riding a bike to a supermarket or office came to his mind. He just expressed it by relating the picture to the picture in his mind about his society.

So, I think it's our thoughts that shape our language, not the other way around.