The present study investigates the use of modal auxiliary verbs in online news comments (YNACC) relative to spoken interaction (SBCSAE) and three written registers (COCA). The central research question that is addressed in the present study is the extent to which the frequency and distribution of modal and semi-modal auxiliary verbs in the register of online news comments are different from those of the spoken and the written registers. The findings of this study indicate that online news comments exhibit higher frequencies of central modal auxiliaries in comparison to spoken interaction and the written registers, not only in regard to the overall distribution of the central modals, but also in regard to the individual distribution of the frequently used will, can, would, and especially should. The findings of this study also indicate that online news comments seem to have adopted the use of semi-modal auxiliaries such as have to and want to from spoken interaction to a much larger extent than the written registers, but that there is no evidence indicating that reductions (i.e. “gonna”, “wanna”, and “gotta”) are in the process of being adopted. The present study is able to demonstrate that there are a number of significant variations in the overall frequency and distribution of the modal and semi-modal auxiliary verbs.