Native speakers of a language know intuitively whether a sentence is grammatical or not. They usually cannot specify exactly what is wrong, and very possibly they make the same mistakes in their own speech, but they know-unconsciously, not as a set of rules they learned in school-when a sentence is incorrect.

Gestures and facial expressions do indeed communicate, as anyone can prove by turning off the sound on a television set and asking watchers to characterize the speakers from the picture alone.

An inability to communicate has little to do with international friction-as is seen in the special ferocity of wars fought between people who speak the same language.

Marriage is simply an economic necessity, and so there are no elaborate courtship displays or marriage celebrations among the Eskimo.

The dictionary is a closed system in which someone interested in the meaning of a word can go around and around and end up exactly where he started, simply because words are defined in terms of other words, and these, in turn, are defined in terms of still other words.

People who speak the same language can hate one another as easily as can people who speak unrelated languages.

The environment does not determine man's culture; it merely sets the outer limits and at the same time offers opportunities.