Small talk is the part of professional English that no course covers and everyone is judged on. It has almost no informational content, which is why second-language speakers often dismiss it — and it does a great deal of social work, which is why dismissing it is costly.
What it's actually for
Not exchanging information. Signalling that you're approachable, that things are normal between you, and that you're a person as well as a function.
That's why the content doesn't matter. Weather, weekend, commute, coffee — the subject is irrelevant and interchangeable. What's being communicated is I acknowledge you and I'm fine with you, which is a real message even though the words carry nothing.
"How are you" is not a question
The most common early misunderstanding. How are you? in passing is a greeting, and the expected answer is Good, thanks — you?
Answering it accurately — describing how you actually are — is a small social error that people notice. If you want to have that conversation, the opening is Have you got a minute?, not the corridor.
The topics that work
Weekend, before and after. Weather, genuinely. Commute or travel. Food and coffee. Something visible and shared — the building, the event, the meeting you've both just left.
The ones to avoid
Salary. Politics. Religion. Someone's age, weight or appearance. Health, unless they raise it. Marital status and whether someone has children, which is normal in many cultures and intrusive in most English-speaking workplaces.
Asking why don't you have children is a genuinely serious misstep, and it's one that lands people in difficulty precisely because it's unremarkable elsewhere.
Scripts are fine here
Small talk is one place where having set phrases is not a weakness, because first-language speakers use set phrases too. Nobody is improvising How was your weekend?
Four or five openers and four or five responses will cover most of your working week.
Learn to end it
Small talk is supposed to be short. Thirty seconds to two minutes.
Anyway, I'd better get on. · Right — see you later. · I'll let you go.
Not knowing how to close makes people avoid opening, which is how someone ends up never speaking to their colleagues.
If you hate it
Many people do, in every language. It's still worth having a minimum version: a greeting, one exchange, a close. Thirty seconds a day with the people you work near.
The colleagues who know you slightly are the ones who include you in things, and that's what the thirty seconds buys.