Politeness leads to civility. It lubricates interpersonal relationships. It also acknowledges someone's place in society and in a hierarchy. Learning how to be polite in any language represents a major step in becoming a skillful speaker of that language. This requires going beyond saying "please" and "thank you." Being deferential means knowing how to exercise linguistic mechanisms that can make greater the metaphorical distance between the speaker and the referent (that is the recipient of the speaker's deference), making reference more indirectly, leaving room for differing opinions, and so forth. The Japanese language is rich in ways of making deferential statements and the evidence for this comes from the earliest historical records.
Choose Different Words
One such politeness strategy often employed is to use politer vocabulary. This is akin to English euphemism of substituting pass away for die in polite situations. In the same vein, in Japanese one may use o- prefixed words (o-mizu 'water'), instead of the variants without it (mizu 'water'). The verb gozaimasu is a politer variant of desu 'be', so Musuko de gozaimasu is politer than Musuko desu 'This is my son.' This is a lexical approach to politeness, because such situations all involve substituting one set of words with politer versions. Another well-known mechanism is the use of courtesy and job titles, such as president, doctor, etc. Japanese makes frequent use of them (e.g., -san attached to one's last name functions much like Ms. and Mr.).
Use Different Grammar
In addition to a lexical approach to politeness, there is also another approach that is based on grammar. There is a politeness strategy to indicate the humbleness or possible inaccuracy of the speaker's knowledge and give credit to the hearer's or someone's superiority (in terms of knowledge, hierarchy, etc.) in a situation. In English, say in a meeting, we often preface our comments by downgrading our own view, as in "in my humble opinion . . ." or "of course I am new and I don't know much about this, but . . ." or "I could be wrong but . . ." These are used, even when the speaker thinks that he is right and the other person wrong, to indicate not only that the speaker will gladly (at least, on the surface) submit to different views, but also to show that he is humble and respectful of other people's views. The humble expressions may be mixed with exalting comments, such as "you have twenty years of experience you know this a lot more than I do, but . . . " or "you have a better handle on the situation than I do but . . ." Both types--humbling and exalting--are employed to make situations less confrontational and therefore more polite. Note that by humbling self and/or exalting others, one achieves an important goal in politeness behavior, that is, creating a greater metaphorical distance between the speaker and the hearer (or other referent). Note also that humbling expressions "demote" the speaker and exalting expressions "promote" the hearer (or the referent). In this essay, I will use ↓ for humbling expression, ↑ for exalting expression, and + for simply polite expression. Japanese employs these three basic strategies frequently and extensively-and these are built into choices the speakers make about which grammatical patterns to use, so that, like the English examples above, they may achieve a certain deferential distance in social situations.