He arrived on __ train and was ready to put his plan into action.
1. The 11.30;
2. A 11.30;
3. 11.30 the;
4. 11.30 a.
He arrived on __ train and was ready to put his plan into action.
1. The 11.30;
2. A 11.30;
3. 11.30 the;
4. 11.30 a.
He arrived on the 11:30 train and was ready to put his plan into action.
The definite article is used because we are talking about a specific train. It was not any old train, it was specifically the 11:30 train.
However, if the train arrived at a train station, and
1/ more than one train arrived in the station at 11:30, and
2/ the speaker is not sure which of those trains that 'He" arrived on,
then it is possible that the speaker may say:
He arrived on an 11:30 train.
Note: In this case we use 'an 11:30 train' not 'a 11:30 train' because 'eleven' starts with a vowel sound.
In standard English the time of the train (or bus, ferry, plane, etc.) is always placed in front of the mode of transport that is arriving.
1: "The 11:30 train". Here's why:
It's a specific train, so it has to be the definite article "the". That eliminates options 2 and 4.
11:30 is here being used as an adjective, and in English adjectives go between an article and the corresponding noun. That means options 3 (and, again, 4) cannot be correct.
There are situations in which one might write "an 11:30 train" (notice that because the next word is "11", which starts with a vowel sound, it has to be "an" rather than "a") but in general that's not idiomatic.