Appendix A

Stimuli and Task Materials

Monologue Story-Telling Task

The monologue task requires participants to deliver a 3-minute uninterrupted story based on a verbal prompt. This task was adapted from the oral production protocol described by Kirk (2016, p. 45).

Administration. Participants receive a verbal prompt from the researcher, are allowed 30 seconds of preparation time, and have a maximum of 3 minutes to speak. All sessions are audio-recorded for later transcription and analysis.

Stimulus Prompts. The following prompts are presented in a randomized order to control for order effects:

Prompt 1: Personal Experience. "Tell a story about a time when you had to solve an unexpected problem. What happened? How did you handle it? What was the outcome?"

Prompt 2: Imaginative Scenario. "Imagine you wake up tomorrow and discover you can speak any language fluently. Tell us what you would do first, who you would talk to, and why."

Prompt 3: Narrative Sequence. "Describe a memorable journey you have taken. Where did you go? What happened along the way? How did you feel during and after the trip?"

Instructions. Participants are told: "You will have 30 seconds to think about your response. Then please speak for up to 3 minutes. There is no right or wrong answer—we are interested in how you express yourself in the target language."

Dialogue Task

The dialogue task involves a 5-minute conversation between the participant and a trained native speaker (confederate). This scenario is adapted from Kirk (2016, Appendix B).

Scenario: Making Plans. The context is a simulated interaction where the participant and native speaker are friends attempting to arrange a meeting.

Native Speaker Script. The native speaker acts as a confederate following a strict script to ensure consistency. The script includes the following key interactions:

The native speaker adjusts responses based on the participant's suggestions (e.g., rejecting Monday/Tuesday, accepting Wednesday). The participant is instructed to ask about availability and negotiate a time that works for both parties.

Recording and Transcription Protocol

Audio recordings are captured using a digital recorder (e.g., Zoom H5) in WAV format (44.1kHz, 16-bit). Files are named using the convention ParticipantID_Task_Date (e.g., P001_Monologue_2026-04-07). Transcriptions follow the CHAT format (Child Language Data Exchange System), and all names are replaced with pseudonyms to ensure anonymity.

Native Speaker Profile

The confederate is a native speaker of the target language with C2-level proficiency. They received a 2-hour briefing on the script and neutrality requirements prior to data collection. The speaker has previous experience in three similar studies and is compensated at a rate of $20/hour.