The capacity for language is unique to humans. Animals can have quite complex communication systems, but it appears that only human language allows us to produce entirely new utterances, things we have never heard, and to talk about things that do not exist (e.g. "Mingo the fairy liked Måns the troll’s new hiphop moustache").

The top-level question for General Linguistics could be expressed as: What sort of thing is language, actually? By using a number of different perspectives, pieces of the puzzle can be found. We look at languages as systems, how they vary (and do not vary) across the world; how languages change over time, and how they are influenced by contact with other language; we study how people use language in social interaction; how language develops in children; what goes on in the brain when we speak and understand language; and lots more. You can read a bit more about some of these areas below.

On comparing languages, and on languages as systems
When we think about languages, we often think first of the words, and how things are called differently in different languages. General linguists study words too: how languages have different numbers of words for colours, for instance; how some languages have no words for ‘there’ which do not also express in what direction, such as upstream vs. downstream; and how meaning changes over time. But traditionally, the main focus area is language structure and how it varies across languages. For example, Swedish and English have prepositions (on the table), but other languages may have postpositions (Estonian: laua peal), and yet others express similar functions in case endings (also in Estonian: linn-as "in (the) town"). The co-occurrence of structures is interesting too; for instance, languages where the verb is clause-final typically have postpositions. A further type of query is the expression of particular meanings across languages, such as ownership (possession); English has "my house" and "my leg", but many languages use different marking for items that you can sell or give away (house), and for body parts and relatives that you don’t shed as easily.

Languages constantly change, and another area concerns the mechanisms of change. Can we work out where postpositions came from? What happens when languages are spoken close to one another for a long time, how do they influence each other? For example, we find the vowel in "heard" in Swedish, German and French but it is unusual outside Europe. Similarly, our perfect tense construction (as in "has written"), where the ownership verb "to have" has become an auxiliary, is uncommon globally. How does the number of speakers and the status of the language factor in?

Language in use
We learn our language from early childhood, from the very start in interaction with people around us, and we use and develop it through life. We use it to exchange information, but our way of speaking expresses a lot more, to do with our identity and social roles; more or less consciously we show that we are from a particular area, are young and cool, masculine or feminine, polite or dominant, and so on. We speak differently in different situations, and many factors are at play.

Language in the brain
Another line of investigation concerns what goes on in the brain when we speak and when we understand language; what processes are taking place, how the various component parts of language are stored in and retrieved from memory, and how different types of injury, aphasia etcetera, impact on these functions.

As language is such a complex phenomenon, its study is strongly cross-disciplinary and it is studied in anthropology, psychology, biology, neurology, and several other disciplines.