The article analyzes some problems of translating syntactical constructions in private legal documents. The purpose of the article is to identify certain isomorphic and allomorphic features of English and Ukrainian syntax in framework of solving particular translation problems.The first isomorphic feature is the length of sentences in the analyzed types of documents. In the process of translation the latter should be analyzed syntactically. The length may be preserved or the sentence can be divided into two or more sentences for better understanding by the reader. Another isomorphic feature is the usage of the Passive voice constructions. The translator can either use them in translation or substitute some of them by the Active forms for reasons of reducing redundant passive structures.In provisos there are a lot of set expressions and formulas in limiting sentences that should be translated without change in syntax relationship. The allomorphic feature in the sentences is the difference in sentence structure. In the process of translation word order can be changed and some transformations are necessary. The comparative analysis showed that syntactic constructions may have common and divergent features that must be taken into account in the process of translation.