This article explores the viability of the analytic distinction between "turn-constructional unit (TCU) continuation" (i.e., continuing a turn beyond a point of possible completion with grammatically dependent material) and "new TCU" (i.e., continuing a turn with grammatically independent material) when hypotactic clause combinations are involved. The focus is on causal clause combinations, which may be either lexico-syntactically marked (e.g., as in English with "because") or lexico-syntactically unmarked but prosodically cohesive. Based on data from ordinary conversation, it is found that both marked and unmarked forms are used in turn continuation, with the unit containing the account (the causal clause) being delivered after the completion of a unit implementing the accountable action. Both marked and unmarked forms of causal clause combination, when used in turn continuation, allow for intervening talk after the accountable; both prioritize the account in establishing relevancies for what happens next. Yet, in current conceptualizations of turn continuation, they would be classified differently, with marked forms counting as "TCU continuation" and unmarked forms as "new TCU." The implications of this unsatisfactory state of affairs are discussed in the conclusion. (Contains 8 footnotes, 2 tables and 6 figures.)