How Gender, Age, Geography has an impact on Language?
All three factors can affect not only how we speak, but what we say. I would argue, though, that gender has the least affect overall of the three. Studies have shown that women tend to use more of their vocabulary than men on average whereas men tend to "conserve words" in conversations. These are not absolutes, of course.
Age has a much greater affect. Because most of our vocabulary is learned before the age of 20, we are greatly affected by the language of that time, and we tend to carry it through the rest of our lives. So you'll hear your grandfather using a slang term or phrase that the younger generation doesn't get at all, and vice versa, of course. Each generation uses its own version of vocabulary.
Geography also has a quite profound effect. Dialects are found in regions, as well as accents. To live and communicate in a particular dialect and accent over time is quite powerful. Most likely, you will start to acquire both. A man who lives in the South in the United States for five years, for example, is more likely to come back speaking with a southern drawl.