Some stores station a clerk at the front door to greet customers. If the greeter says, “Welcome to Macy’s,” it is polite to answer, “Thank you.” If the greeter says, “How are you folks today?” it is polite to respond, “Fine, thank you.” Once in a store, you may discover lots of clerks waiting to be of service. If you are browsing and one asks you, “Can I help you?” you can just reply, “No, thank you. I’m just looking.” You are just as likely to discover that there is no clerk around when you need one. The store has obviously decided that their customers do not want clerks hovering over them. In that case, you may have to hunt for a clerk to ask, “May I try this on?” or “Where can I pay for this?”