We investigated the preparation of a spoken answer response to interrogative sentences by measuring response time (RT) and the response-related readiness potential (RP). By comparing the RT and RP results we aimed to identify whether the RP-onset is more related to the actual speech preparation process or the pure intention to speak after turn-anticipation. Additionally, we investigated if the RP-onset can be influenced by the syntactic structure (one or two completion points). Therefore, the EEG data were sorted based on two variables: the cognitive load required for the response and the syntactic structure of the stimulus questions. The results of the response utterance preparation associated event-related potential (ERP) and the RT suggest that the RP-onset is more related to the actual speech preparation process rather than the pure intention to speak after turn-anticipation. However, the RP-onset can be influenced by the syntactic structure of the question leading to an early response preparation.