The Notion of Linguistic and Non-linguistic Typology The word typology consists of two Greek morphemes: a typos means type and b logos

Formal universals are a set of abstract conditions that govern the way in which a language analysis can be made - the factors that have to be written into a grammar, if it is to account successfully for the way sentences work in a language. For example, because all languages make statements and ask related questions (such as ‘The car is ready vs Is the car ready? some means has to be found to show the relationship between such pairs. Most grammars derive question structures by some kind of transformation. (In the above example move the verb to the beginning of the sentence.) It is claimed that such transformations are necessary in order to carry out the analysis of these (and other kinds of) structures, as Chomsky theory does, then they would be proposed as formal universals. Other cases include the kinds of rules used in grammar or the different levels recognized by a theory.
Comparative typology is a branch of general linguistic typology. It deals with a comparison of languages.
Since the end of 18^th century, the chief concern has been to explain the nature of linguistic diversity. This was the focus of comparative philology and dialectology, and it led to early attempts to set up genetic and structural typologies of languages.
Comparative method is a way of systematically comparing a series of languages in order to prove a historical relationship between them. Scholars begin by identifying a set of formal similarities and differences between languages and try to work out (or reconstruct) an earlier stage of development from which all the forms could have derived. The process is known as internal reconstruction. When languages have been shown to have a common ancestor they are said to be cognate.