I believe this depends on the length of the interview. For questions like “Why law?” or “Why this firm?”, you should aim to spend two to three minutes answering each in a thirty-minute interview. That’s enough time to make your points clearly without dragging on. If the interview is longer, such as an hour, you can take closer to three to four minutes to add a bit more detail.
The key is to hit your main reasons quickly and confidently. Start with your strongest point first. For example, with “Why law?”, lead with what sparked your interest or what keeps you motivated. Then follow with something more personal or reflective to show depth. For “Why this firm?”, focus on specific things that set them apart, like their work in a particular sector, and link that back to your career goals.
Practising how you deliver these answers is crucial. Your vocal tone and confidence in what you are saying will make all the difference. A strong start will help prevent interruptions and keep the conversation flowing naturally. Another thing is to not practice too heavily for such questions - and I appreciate this may sound contradictory to all I’ve said. Pre-prepped answers can always be caught, and you want these passions to sound natural. You should still know your main drivers from within though, and fall back on these during the interview.
The idea is to balance being concise with showing that you’ve put thought into your answers.