The classroom is an important context of second language learning for language minority children. Teachers are responsible for creating good learning opportunities by securing language use well adjusted to the children's level of comprehension. Thus, teachers should have realistic expectations of this. The purpose of the research is to increase knowledge of the classroom as a language learning setting by exploring the accuracy of teachers' evaluations of their students' language comprehension and possible biases in their evaluations of language minority compared to majority students. A total of 205 students from 13 different classes and their main teachers from five different schools in Norway participated in the research. The students were tested for vocabulary and grammatical comprehension of Norwegian, and their teachers were asked to predict how each child would score on each test item. The language minority children gained lower scores than the majority children, a difference also predicted by their teachers. The accuracy of teachers' predictions was higher for language majority than minority children, however. This difference seems to be directly affected by the language minority/majority status of the child. The teachers were, furthermore, most accurate when predicting the comprehension scores of the students they believed to be high performers.