“Claim”

The word “Claim” is one of the most misunderstood words, as far as Japanese speakers are concerned.

It doesn’t simply mean “complain”. The sentence, “My customer claimed,” is meaningless, because “claim” needs an object (it is a transitive verb). The sentence needs to explain what the claim was. For example, “My customer claimed that the goods were faulty.”

“Complain” is intransitive, and so can be used without an object: “My customer complained.” If you want to give an explanation, you can say, “My customer complained that the goods were faulty,” or “… complained about the faulty goods.”

“Claim” doesn’t even need to be something bad; just unverified, and perhaps doubtful. For example, “She claims that she can speak Chinese, but I have never heard her speak it.”

Other common uses for “claim” are “baggage claim” and “insurance claim”, where the speaker is claiming the right to receive the suitcase/money.

So, if you want to say that your customer isn’t satisfied, without giving details, use “complain”.