Polite British Grammar for Questions / Instruc…

Polite: Please write the report for me by tomorrow.

Even more polite: Please could you write the report for me by tomorrow.

Polite form: please + verb (bare infinitive) is ok, but for British people even this can seem too direct, especially at work.

Even more polite form: please + could + subject + verb (bare infinitive) – using ‘could’ makes everything more polite. In a British work setting, this feels more comfortable.

Polite: Please open the window.

Even more polite: Please could you open the window.

via: http://www.learnbritishenglish.co.uk/