POLITENESS IN DIRECTIVES
After an imperative, a modal tag acts as an intensifier, either softening or heightening the insistence of the directive. Will you? and could you? convey a high degree of optionality while can’t you? questions the hearer’s apparent inability to do something, conveying impatience and low optionality. The more optional the act appears to be, the more polite is the request.
Intonation and the words used can make even will you less polite, however; Shut up and Drop dead don’t become polite by adding will you. Rising intonation is typically polite and persuasive, failing intonation more insistent.
Check this for me, will you? polite, anticipates willingness
Sign this for me, would you? polite, anticipates willingness
Keep this for me, can you? familiar, anticipates willingness
Hold this for me, could you? less familiar, anticipates willingness
Keep quiet, can’t you? insistent, anticipates unwillingness
These examples are characteristic of contexts of familiarity. With the exception of can’t, they question and anticipate the addressee’s willingness to carry out the action, and are polite but familiar, expressing solidarity. The negative imperative tag will you? is also familiar as in Don’t be late, will you?, while the invariable tag mind is more insistent: Don’t be late, mind!
Where there is no relationship of closeness between the speakers, these forms may sound over-familiar. In such cases most modalized interrogatives are safer without tags.
