In this work we deal with the position of obsolescent words, obsolete words and historicisms in the teaching of the Czech language and literature at the lower level of a one-year grammar school. We focus on layers of vocabulary, especially on the layer of time-tagged words, we explain the terms obsolescent word, obsolete word, archaism and historicisms in the theoretical part. We also focus on the reading comprehension process. We describe the ways in which readers deduce the meaning of unknown words. We analyse the system of curricular documents, textbooks and readers used at the lower grades of eight-year grammar school by the method of detailed reading in the practical part. Based on the results of the questionnaire survey, we also analyse the knowledge of pupils, their attitude to these words and the influence of the occurrence of these words on their reading and understanding.