Specialised discourses manifest the organising thoughts of the discourse community that speaks the language.  They are formed by a series of interrelated linguistic properties that are joined in sentences by small but very important lexico-grammatical properties - colligations of prepositions. This paper reviewed the linguistic properties that constitute these linguistic patterns (colligations of prepositions) as well as their semantic and pragmatic functions in legal discourse. The literature reveals that prepositions have both the lexical and grammatical statuses. They are prevalent in legal texts, and they play very important role in conveying the thoughts of the discourse community of the law. Proficient linguistic users are marked by having competence of these patterns. Due to the importance of colligations of prepositions in legal discourse, it is recommended that law students and legal scholars be taught colligations of prepositions explicitly rather than learning them implicitly.