Most interview advice tells you to "just pause instead of saying um." That's not wrong, but it could be formulated in a much more useful way. Filler words aren't a speaking problem. They're a thinking problem. You say "um" because you're partway through a sentence without knowing how it's going to end.
That's the part most prep advice skips, and it's the part that actually fixes things.
The real skill isn't pausing, it's planning ahead
When you know where a sentence is going before you say the last few words, two things happen. First, you stop needing filler words to buy yourself thinking time, because the thinking already happened. Second, and this is the part almost nobody mentions: you gain control over how the sentence lands.
Here's why that matters. A sentence that trails off or stops abruptly reads as uncertain, even when the content was solid. A sentence where your tone drops deliberately at the end signals "that's my point, I'm done" and reads as decisive and composed. Most candidates never think about this because they're focused entirely on what they're saying, not how it lands. Interviewers pick up on both, whether or not they could explain why.
How to actually build this, outside of mock interviews
Mock interviews matter, but they're not where this skill gets built. They're high-pressure and infrequent, which is exactly the wrong environment to develop a habit. The actual training ground is low-stakes, everyday talking: explaining your weekend to a friend, telling a story at dinner, narrating what you're doing while you cook. None of it needs to be eloquent. What it needs is volume of reps where you're paying attention to whether you know your ending before you get there.
This sounds almost too simple to matter, but it's the difference between trying to think on your feet for the first time when the stakes are highest, versus walking in with a skill you've already built somewhere safer.
A simple drill, if you want a starting point:
Pick a basic interview question, something like "tell me about a project you're proud of."
Answer it out loud, record yourself if you can.
Listen back for two things only: did you know your ending before you got there, and did your tone drop on purpose or just fade out.
Repeat the same exercise in ordinary conversation this week, not interview prep, just regular talking, and pay attention to the same two things.
You're not memorizing an answer. You're training the part of your brain that plans ahead while you're still talking, which is the actual skill filler words are covering for.
Why this gets overlooked
Most prep advice focuses on content: what to say, which framework to use, how to structure an answer. Almost none of it touches delivery mechanics like this, because it's harder to coach and doesn't fit neatly into a checklist. But in a real interview, delivery is doing as much work as content. Two candidates can give answers with identical substance, and the one who sounds decisive walks out with a better impression than the one who sounds like they're improvising.
This is one piece of a longer list of small, deliberate adjustments that change how an interview actually goes — not generic confidence advice, just attention to the mechanics most people never examine. If you want a second set of ears testing this against a real mock session, that's literally what we do: interviewprephq.com