What do we mean by ‘sign languages’? What are the specificities of sign languages? In what way, sign languages may contribute to general linguistics? Linguistics has undergone remarkable developments during the last decades; however Sign languages constitute a challenge particularly for the field of linguistic typology. The aim of this paper is to show that French Sign Language (langue des signes française, LSF), beyond its structural and functional specificities share a lot typological characteristics that are found in many spoken languages of the World of as well as in some written logographic systems. General typology shed new light on Sign languages and shows that beyond functional specificities related to the visual-gestural modalities, this language displays a number of morphological and syntactic types attested many spoken languages. There is allegedly at least 136 Sign languages in the World but some sources provide a much higher figure of nearly three hundred. The genetic classifications of Sign languages are still imprecise and the grouping of SL into families does not enjoy a consensus. A great number of SLs do not allow mutual understanding. SLs are minority languages without precise geographic location. They are silent languages that share some features of the written logographic systems but do not have any written system. SL makes use of two entirely different types of “signs”, standard signs and transfers. Sign may be analyzed according to several parameters. Each area of the signing space is significant. Sign languages are spatial and « situational ». The preferred syntactic order in LSF is: Agent-Patient Predicate (« SOV »). Concerning lexical categories, it is necessary to distinguish three categories in LSF: nouns, verbs and to a lesser extent, adjectives. Other categories such as adverbs or adpositions play a marginal role. LSF does not have any grammatical gender or article. Number is optional. There are various types of pronouns which are essentially marked through pointing signs and eye-gaze. Among the typological features that we discuss in this article, we can mention classifiers or pro-forms, nominal incorporation, various verb classes, the high semantic resolution of some verbs, the absence of non-finite forms of verbs, the absence of copula as well as the adjectival category. The list of typological characteristics presented here is of course not exhaustive. Moreover, in order to allow a typological comparison with spoken languages, we focused on « Standard signs » and did not discuss in depth iconicity, which is a fundamental feature of LSF and other sign languages. In sharp contrast with the clichés and stereotypes shared by the general public as well as by a number of linguists, LSF has a complex grammar which has not been described in detail. This paper strives to show the necessity of typological approach for the analysis and description of LSF, but it also demonstrates the great interest of this language for general typology. Let’s hope that this overview of categories in LSF will contribute to draw attention to sign languages from a growing number of linguists and particularly typologists. These languages are often forgotten in the general discussion about Human language despite the fact that they offer a great challenge for linguistic theories as well as other fields of Human sciences such as sociology, anthropology, psychology and epistemology.