When do I stop?

In many parts of the world it is called a full stop. In the US it is called a period. We used to see them a lot more than we do these days. Where have they gone? And when do we use them? There's a summary at the bottom if you want to go to the cheat sheet. Otherwise...

You need one at the end of a sentence. It tells us to stop, take a breath and then move on to the next sentence. Everyone knows that, right? Well, yes, but sometimes when we are writing we get confused about where one sentence ends and another begins. That's when we end up with a run-on sentence. For example:

It was raining hard my umbrella was at the bottom of my school bag.

The two ideas just don't go together in that one sentence. Don't you miss that pause a full stop gives you? You need something to go between those two ideas. A full stop would be perfect:

 It was raining hard. My umbrella was at the bottom of my school bag.

Easy! So what else needs a full stop? In Commonwealth countries the answer to that used to be quite complicated. But now we seem to be aiming for a less cluttered look in our writing, with full stops among the first to go. 

The only abbreviation we still use a full stop for is 'no.' for 'number' (strictly speaking it isn't an abbreviation but a contraction of the word numero). The full stop is there to ensure 'no.' doesn't get confused with 'no'. Just remember to leave the full stop out if you are referring to more than one number ('nos'). 

Finally, we still use the full stop in some Latin abbreviations. It pays to check your dictionary for these. Sometimes a dictionary will have two choices. Just go with the first option as that is the more common usage. The most common Latin abbreviations we use are punctuated like this:

• a.m. (or am)
• p.m. (or pm)
• e.g.
• i.e.
• etc.
• c. 
• NB
• PS 

What do you need to remember when using a full stop?

1. Use it at the end of a sentence to tell your reader to take a pause.
2. Use it to avoid run-on sentences.
3. Use it for 'no.' (number).
4. Use it for some Latin abbreviations (check your dictionary).