Word formation/Compounding

Compounding is the process which probably characterises English the most. Compounds are formed by combining two, or more, already existing words into a new one. The graphical form of its constituents remains unaltered (which is not always the case for their phonological form — changes often occur on the level of suprafixes, that is regarding tone or stress): chairlift, ashtray, fast-food, dry-clean, sex symbol, sewage disposal works. English compounds very in their orthography and can be constructed out of more than two constituents. They can be either spelled together, separately or be hyphenised — the rules regarding a preferred form are not clearly internalised, although there are some tendencies in frequency of particular forms.

Structure
What is common for compounds, however, is their structure. Each consists of a head and a modifier. The head of a compound is the part that is more important than the other in a way it determines the word-class of the whole word and takes inflectional endings. It also follows the general rule of importance of meaning — that is, the more meaningful or important a constituent is, the more likely it will be placed at the end of a given structure. Hence, we can conclude that in English compounds are generally rightheaded — in the example of fast-food, the whole word denotes 'a kind of food' rather than any attempt to describe a way of 'being fast'. Also, since the morpheme food is a noun, the whole word belongs to the very same word-class. What remains is the lefthand of a compound, namely the modifier. Modifiers are characterised by being applied stress onto, which helps us distinguish them from other constructs — a 'blackboard is 'a board that teachers write on', while a black 'board is any board that happens to be black — which is not necessarily true for the former.

Productivity
The vast majority of English compounds are nouns. However, the productivity of this process allows to create items that vary greatly in word classes they belong to — there exists a considerable number of combinations of grammatical categories one can choose from when merging them into compounds, and this is the basis for establishing the primary classification of compounds. There is a category of compounds, though, that contain constituents of a slightly different character. What is meant here is that they not only can be attached to bases like bound morphemes (affix-like behaviour), but can also be combined with themselves. These abound in the medical and scientific terminology and often stem from Greek or Latin, and some examples include astro-, electro-, hydro-, -ology, -photo, bio-. What is more, they often function on their own in the linguistic word, which effectively narrows the meaning of a newly-coined word that is created by combing these segments. Such constituents are labelled 'combining forms' and form a structure called neo-classical compounds.