The article contributes new data and findings to the growing field of corpus-based dialect syntax research. The focus of the paper is on variation in ‘need’-constructions (tarvis/vaja olema+ nominal complement/infinitive ‘need to’) based on the corpus of Estonian dialects. Our purpose was to demonstrate the complex nature of syntactic variation, constrained geographically, individually or by language-internal factors. The study takes a corpus-based quantitative approach to observing the geographical spread of linguistic units. We apply conditional inference tree and random forests models to capture the (co)varying parts of the construction studied. Our results show that variation in different parts of constructions is influenced by different factors, both geographical and language-internal. Lexical variation (adverbtarvis‘need’ orvaja‘need’) and omission of the copula are clearly geographically distributed, while omission of the experiencer is determined mainly by language-internal factors. However, the study has also found extensive inter-individual differences.

中文翻译：

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爱沙尼亚方言中“需要”结构的句法变化

这篇文章为不断发展的基于语料库的方言句法研究领域提供了新的数据和发现。本文的重点是“需要”结构的变化（塔维斯/瓦哈奥莱玛+ 名义补语/不定式“需要”）基于爱沙尼亚方言的语料库。我们的目的是展示句法变化的复杂性，受地理、个体或语言内部因素的限制。该研究采用基于语料库的定量方法来观察语言单位的地理分布。我们应用条件推理树和随机森林模型来捕捉所研究结构的（共同）变化部分。我们的研究结果表明，结构不同部分的变化受到不同因素的影响，包括地理和语言内部因素。词汇变体（副词塔维斯“需要”或瓦哈'need'）和连词的省略在地理上分布很明显，而经验者的省略主要由语言内部因素决定。然而，该研究也发现了广泛的个体间差异。