Throughout history, scholars have questioned the authenticity of Khayyam’s quatrains. They proposed a variety of means and methods to determine the authentic quatrains of Khayyam. Among them, some elements and criteria can be mentioned: resorting to reliable and ancient resources, key quatrains, the principle of congruence, rhyme scheme, and studying on the basis of style, language, themes and concepts. Looking at the research background, it can be understood that a few research has been done on Khayyam’s linguistic and stylistic features. In this research, we intend to examine the linguistic signs of lateness in the quatrains attributed to Khayyam. In this study, an attempt has been made to supplement the studies of researchers who have often considered manuscript issues in determining the age of Khayyam's quatrains by using linguistic criteria. Given that linguistic criteria are more helpful to researchers in a negative approach and can be used more to determine the lack of authenticity of a text than to determine its authenticity. Therefore, as is clear from the title of the article, works attributed to Khayyam are examined here, not works whose age or authenticity has previously been determined in various ways. The main hypothesis is that some linguistic features can lead us to the time of poems’ composition, because there is a direct relation between the presence of these features in texts and the time of composing them. The research findings show that the presence of some linguistic features that were uncommon in the Khayyam’s era may indicate that the attribution of some quatrains to him is incorrect.