I've always felt like the ability to understand and interact well with another culture requires learning their language. There are concepts and ideas that are only reflected well in the native langauge of those concepts and ideas and if one attempts to access them through their own language and a translator, they cannot truly understand them.
I've been told the same applies to studying philosophers like Kant and Heidigger when their works have been translated into English. To really get the whole idea of what they were trying to say one must study them in their native German.
The claim can also be used to validate the importance of the arts, as means of expression that do not necessarily require spoken words. An artist may use color and form and texture to express sensations that cannot be put into words. Instrumental music can create feelings and emotions that are beyond mere speech.
This statement is particularly true for higher level learning and specific areas of knowledge. We cannot discuss literature unless we all know and understand specific terms. For example, it would be difficult to discuss the Romanticism movement unless those involved in the discuss knew and understood what that movement entailed. We need terms and vocabulary in order to facilitate a specific genre. Another example of the need for vocabulary can be found in the sciences. We cannot discuss scientific studies unless we all know and understand how these studies are carried out. If we did not have words like hypothesis, theory, and scientific method, we could not conduct research effectively. Vocabulary becomes more and more important the more in depth we delve into a particular area of study.
George Orwell said that a person cannot have great thoughts without a great vocabulary. How, indeed, can one express an idea without the words that are appropriate to this expression? Reciprocally, how can one have a sophistication of thought without a sophistication of vocabulary. One needs only study the history of advanced civilizations to understand that the language and thoughts of these civilizations, too, are advanced.
The sociologist Robert Bellah has made a very similar comment when it comes to our understanding of community. One of his best argument in his book, Habits of the Heart, is that because our nation is so individualistic that we lack a vocabulary to speak of communal living, as other parts of the world do. This makes good sense, because our radical individualism has shaped our thoughts to live even more individualistic lives. For this reason, we lack an in depth understanding of community.
This argument has been central to much thinking in most of the social sciences and humanities in the past half century. It has been associated not only with the thinkers mentioned above but with many others as well. This helps explain the so-called "Linguistic Turn" in philosophy. It also helps explain the phrase "The Prison-House of Language." In practically every area of thought, the idea that language does not merely express thinking but shapes it has become highly influential. As might have been expected, this is also a hotly debated issue. For further information about the debate, please follow this link:
Pohnpei's man-woman example is a very good one. This idea has most recently influenced structuralists, who have argued that we can't do things we can't say we can do. Claude Levi-Strauss, Jacques Derrida, Michel Foucault, and others explored the ways that language limits and reflects human action in the 20th century. Their arguments influenced historians, psychologists, and anthropologists, to name a few disciplines. Historians are particularly interested in it because (some argue) if you can show that language changes over time, you can demonstrate changes in mentality. And it's not that hard to show how language changes over time.
This makes a lot of sense and this idea goes back as far as Plato, who said that we don't really see reality but just shadows of reality. By that theory, when we talk or even think about things, we are only thinking about our words for them, which is different from the reality.
As far as examples, this is difficult because we obviously cannot talk about things that we don't know about. However, we can point to areas where our vocabulary influences our thinking. For example, we have a word for "man" and a word for "woman" and no other words until recently for people who are somewhere in between. This conditions us to think that people must either be men or women in order to be normal and natural.