The last decades are marked with an increasing interest towards the study of isoglosses shared by some branches of the Indo-European language family. As is well-known, next to well-established branches such as Germanic, Greek or Indo-Iranian, there are larger subdivisions within Indo-European, grouping together several branches, in accordance with a number of features, traditionally called isoglosses. Such features are shared by more than one group, or by several languages which do not belong to the same group (branch-crossing isoglosses). Such isoglosses have always been at the focus of vivid debates in Indo-European scholarship, giving rise to numerous hypotheses on early splits within Proto-Indo-European or, on the contrary, later contacts among historically attested languages. A systematic research of these issues still remains a desideratum. Next to a few notorious isoglosses, almost exclusively limited to the phonological level, such as the kentum/satəm division,1 or the ‘ruki’ division (retraction of the sibilant s), which have been known for about a century, there are a few less studied morpho-syntactic features, often of a much vaguer nature, that equally group together a number of branches and/or languages. One

中文翻译：

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印欧语素的句法同义词简介

在过去的几十年中，对印欧语系一些分支机构共享的等距语言的研究兴趣日益浓厚。众所周知，在日耳曼语，希腊语或印度-伊朗语等成熟的分支机构之后，印欧语区内有​​较大的细分，根据许多功能（通常称为等距）将多个分支组合在一起。这样的功能由多个组或不属于同一组的几种语言（分支等距）共享。这种等古迹一直是印欧学术界激烈辩论的焦点，引发了关于原始印欧语系内部早期分裂的许多假设，或者相反，后来有历史证明的语言之间的交往。对这些问题的系统研究仍然是我们的愿望。除了一些臭名昭著的等音线外，它们几乎仅限于语音学层面，例如，已知的肯特姆/饱和度（Kentum /satəm）分部1或“ ruki”分部（使sbilant缩回）已经有一个世纪的历史了。很少研究的语素-句法特征通常很模糊，它们将许多分支和/或语言平均地组合在一起。一