"The" in fixed expressions

[Rachel Adams]

Hello.

Is is always "At the concert" not "At a concert" because it's a fixed expression? Just like "At the station", "At the doctor's" etc.
"Were there many people at the concert last night?"
It's from "Essential Grammar in Use" by Raymond Murphy.

 

[PeterCW]

It's only "the concert" if you know which concert is being discussed.

 

[Rachel Adams]

It's only "the concert" if you know which concert is being discussed.

Are "at a station" and "at a doctor's" also possible in the right context? For example, "I met her at a station." If mention them, "station" and "at a doctor's" for the first time.

 

[PeterCW]

Are "at a station" and "at a doctor's" also possible in the right context? For example, "I met her at a station." If mention them, "station" and "at a doctor's" for the first time.

In colloquial BrE the surgery that you normally attend would be "the doctor's" without any need to establish that you are talking about your own doctor.

 

[Rachel Adams]

I agree. I merely noted that 'at a doctor's' is possible.

So the definite article in these expressions which I asked about and in my new sentences shows that we are talking about specific places. Am I right? For example, "On the bus" and "on the train". "I came home on the bus." "I had a meal on the train." If it is because the person who is speaking is on the specific train and bus which he is speaking about, I can understand it , but "Essential Grammar in Use" by Murphy shows a man in the picture and says "He is in a plane" and in another picture it says "They are at a wedding." Not "At the wedding" or "On the plane."
The complete sentences are here:

1. "Are you hungry after your journey?" "No, I had a meal on the train."

2. "I walked to work but I came home by the bus."

 

[Rachel Adams]

1. The first speaker presumably knows that the second's journey was by train, so 'the train' can suggest "the particular train on which I was travelling.
2. This one is slightly unusual - I'd expect 'by bus'. 'By the bus' suggests a particular bus know to both parties in the conversation.

I have to warn you that if you are looking for rock-hard rules on the use of articles, you are going to be disappointed. In some cases, we have a lot of leeway.

Oh, yes. I know that. Then if we have the definite article with "bus", "train", "plane", etc it suggests that the word was mentioned before, doesn't it?

 

[GoesStation]

Oh, yes. I know that. Then if we have the definite article with "bus", "train", "plane", etc it suggests that the word was mentioned before, doesn't it?

I'm afraid not. I hasten to add that this is not my fault.

 

[Tarheel]

It's not his fault. It's my fault. ;-)

If I say "I took the bus" I am not talking about any particular bus. I took the bus that came by while I was at the bus stop