Vagueness in software requirements documents can lead to several future maintenance problems, especially when the customer and development team do not share the same language. Currently, companies rely on human translators to maintain communication and limit vagueness by translating the requirement documents by hand, which is expensive and time consuming. Because of that an automatic solution is desirable to reduce this effort. In this thesis, I present two approaches to identifying vagueness in requirements documents in a multilingual environment. Subsequently, I conduct two studies of these approaches for calibration purposes. In the first study, six participants, two native Portuguese speakers and four native Spanish speakers, evaluated both approaches. Then, I conduct a field study to test the performance of the best approach in real-world environments at two different companies.