“When was the last time you got a haircut?”
You're sitting at home with your husband. You notice that his hair is getting long, and it needs to be cut., so you ask him this.
When was the last time you got a haircut?
This is an extremely useful question to ask when you want to know when something happened most recently.
When was the last time we saw each other?
When was the last time it snowed in May?
When was the last time we ran into this kind of problem?
In the example above, the speaker is using "When was the last time ___" to nag her husband. This phrase is very common for nagging and criticising people:
When was the last time you washed the dishes?
When was the last time you took a shower?
You can also include "that" in these questions. This is more correct for written English and sounds more formal.
When was the last time that you got a haircut?
Most people go to a professional stylist or barber when they want a haircut. You describe this service as:
I got my hair cut.
I got a haircut
Sometimes people will also say:
I cut my hair.
But that's a little confusing because it sounds like you did it yourself.
Aside from getting your hair cut, other services that you can "get" include: