Telling time means the person has to divide a clock into right and left halves. Obviously I am talking about your standard dial as digital clocks can be read differently. This is never explained in language books and I have looked through many. Never rely on the student's common sense; if there are a few minutes past the hour tell him that the time is that many minutes after or past the hour. I understand there are distinctions to be made between the use of "after" in America and "past" in Britain so being in Canada gives us the opportunity to use both words.
It is easier to tell the time on a digital clock just by reading the number from left to right and reading the hour distinctly from the minutes. So 5:20 will be read as five, twenty.
The half hour mark will be read as a half past that particular hour or the hour will be read and the number thirty. Thus 5:30 is either five thirty or half past five. If the speaker wants to distinguish between the morning and afternoon he should say either am. or pm. respectively after the time. Am. stands for anti-meridian, and pm. for post-meridian.
Once the time has past the half hour mark then the time should be read as the number of minutes left to the next hour. So 5:49 pm. will be read as eleven to 6. It is not necessary to say pm. Especially if it understood you are talking about a time in the afternoon.
Students should be conscious that once twelve is reached in the middle of day that is called noon and then one uses the notion pm. and not am. Similarly once midnight is reached, the speaker should use the 12 am. notation.
