The Exact Hour: the Number Before o’clock
When the clock shows 00 minutes, say the hour and add o’clock. This names the time shown on the clock, not a duration: the word hours does not replace o’clock here.
A complete statement begins with It is or It’s. Both forms are appropriate. The apostrophe in o’clock is part of its spelling.
It is / It’s + hour + o’clock.
It's six o'clock, and the room is quiet.
It is six o'clock, and the room is quiet.
6:00: o’clock comes after the number. Without context, it is not clear whether this is morning or evening.
It is four o'clock, and I am here.
It is four o'clock, and I am here.
The full form It is can also introduce a statement about the time.
Half an Hour: half past Before the Number
For 30 minutes, use half past and name the hour after which this half has passed. At 6:30, six o’clock has already begun, and seven o’clock has not yet arrived.
Do not rearrange the words. After half past, do not add o’clock: this expression already names the minutes.
It is / It’s + half past + hour.
It is half past six, and the door is open.
It is half past six, and the door is open.
6:30 — half past six.
It is half past eleven, and I am hungry.
It is half past eleven, and I am hungry.
The number eleven names the hour that has already begun.
A Forward-Looking Hour in Some Time Expressions
To express 4:30, first identify the digital time: 4:30. English names four because half past counts the minutes after four.
The rule does not change after twelve: 12:30 is half past twelve, and the English formula names twelve.
At half past four, I am in the garden.
At half past four, I am in the garden.
The time is 4:30; English names four, the hour that has already begun.
At half past twelve, we are in the kitchen.
At half past twelve, we are in the kitchen.
This refers to 12:30; the number does not change to one.
From Clock Hands to a Statement
The long minute hand at 12 means 00 minutes, and at 6 it means 30 minutes. The short hour hand shows which hour to name. At half past, it is between two numbers: choose the one it has already passed.
For the current time, use It is / It’s. For the time of an event, add at before the time expression. This helps distinguish the time shown on a clock from a scheduled event.
The lesson begins at six o'clock.
The lesson begins at six o'clock.
An event at 6:00: at comes before the time expression.
Our break ends at half past one.
Our break ends at half past one.
1:30: the minute hand is at 6, and the hour hand is between 1 and 2.
Two Formulas Are Not the Only Ways to Tell the Time
Here we practise only exact hours and half past. In exercises, the words o’clock or half past may be explicitly required to practise these particular formulas. Other natural ways to say the same time are not therefore grammatical errors.
Digital readings of the hour and minutes are also possible; half past is especially common in British usage. In informal British conversation, you may hear half without past, but in these exercises we use the full formula. Quarters and forming questions about the time independently belong to separate rules.
We eat at six thirty.
We eat at six thirty.
A grammatical digital reading of 6:30; the target exercise may require the formula with half past.
At five o'clock, the room is empty.
At five o'clock, the room is empty.
The expression for an exact hour remains the same at the beginning of a sentence.
Common mistakes
Incorrect:The café opens at o'clock seven.
Correct:The café opens at seven o'clock.
In the expression for an exact hour, the number comes before o’clock.
Incorrect:Our call is at half to six.
Correct:Our call is at half past six.
The full formula for 6:30 contains past: the minutes are counted after six.
Incorrect:We eat at half past ten o'clock.
Correct:We eat at half past ten.
For 10:30, do not add o’clock to an expression that already includes minutes.
Incorrect:It is eight and half, and we are tired.
Correct:It is half past eight, and we are tired.
The word order and half is not used to name 8:30; the required order is half past + hour.