In different spelling systems, different grades of morpheme constancy can be found: German has a high degree of morpheme constancy (especially stem constancy, for example rennen – rennt both forms with <nn>), while English has comparatively less (running – run, only the disyllabic form with <nn>). This paper investigates the interaction between stems and verbal inflectional suffixes in terms of constancy in three Germanic languages (Dutch, English, German) and five Romance languages (French, Italian, Portuguese, Romanian, Spanish). Verbal inflection is always the most widespread inflection, so it is a well-defined area for getting an idea of how spelling systems may function. For the Germanic languages, this analysis will primarily focus on the alternation between monosyllabic and disyllabic forms. For the Romance languages, it will focus on the <c>/ <g>-alternations in interaction with the following vowel. The aim is to describe a scale of morphological spelling: The alternation of <c> and <ç> is not an instance of constancy, but of similarity, something between constancy and non-constancy. Morpheme constancy is no longer a binary feature. Comparing verbal inflection takes us another step towards the development of typological parameters for visible morphology.

在不同的拼写系统中，可以发现不同等级的语素常数：德语具有较高的语素常数（尤其是词干常数，例如rennen – rennt都以<nn>形式出现），而英语的语素常数则相对较小（运行–运行），只有带<nn>的双音节形式）。本文以三种日耳曼语（荷兰语，英语，德语）和五种罗曼语（法语，意大利语，葡萄牙语，罗马尼亚语，西班牙语）的不变性来研究词干和言语拐点后缀之间的相互作用。言语变化总是最普遍的变化，因此它是一个明确定义的区域，可用于了解拼写系统的功能。对于日耳曼语系语言，此分析将主要着眼于单音节和双音节形式之间的交替。对于浪漫语言，它将着重与以下元音交互作用的<c> / <g>替代形式。目的是描述形态拼写的范围：<c>和<ç>的交替不是恒定性的实例，而是相似性，在恒定性和非恒定性之间的某种关系。语素不变性不再是二进制特征。比较言语拐点使我们向可视形态学类型学参数的发展又迈出了一步。