Japanese people need help to brush up on their polite language, a government panel has proposed.
Shop assistants should speak differently to customers
A report for the Agency for Cultural Affairs said 'keigo' - honorific Japanese - was being widely misused.
Keigo is a complicated form of the language which involves different conjugations of regular nouns and verbs, or different words entirely.
It is used to address seniors - a customer, for example - and is meant to humble speakers and elevate listeners.
The government panel has proposed publishing manuals explaining to people how the language should be used.
"Not just young people, but grown-ups are not using honorific Japanese properly. With the language guidelines, we hope to spread the correct use of the Japanese language," education ministry official Osamu Kubota was quoted as saying by the French news agency AFP.
The government panel cited a 2003 survey on the Japanese language which found that 96% of people believe keigo remains important, but the researchers noted that it was nevertheless being used incorrectly.
It tends to take far longer to say something formally in Japan.
For example, the verb "to be" is iru in informal Japanese, imasu in polite Japanese, and irasshaimasu in honorific Japanese.
The government report also suggested that the country's ability to read and write Chinese characters - the mainstay of the Japanese language - be re-evaluated.
A survey in November found that 20% of students at private universities had poorer language abilities than high school pupils.
Adults sometimes find it difficult to remember how to write characters because they rely on computers, and have to ask their children for help.