E. in the train; in the sun (sunshine); in the shade; in the dark; in bed weather etc. (e.g. We sat in the shade. It was too hot to sit in the sun.)
a. (write) in ink; in biro; in pencil; (write) in words; in figures; in BLOCK CAPITALS etc. (e.g. Please write your name in block capitals.)
b. (be/fall) in love (with somebody) (e.g. Have you ever been in love with anybody?)
c. in (my opinion) (e.g. In my opinion, the film wasn’t very good.)
E1. At the age of ~ etc. We say ‘at the age of 10; at 100 miles; an hour; at 0 degrees etc. (e.g. Tracy left school at 18. or the age of 18.)
E2. On holiday/ on a tour etc. We say (be/go) on holiday/ on business/ on a trip/ on a tour/ on a cruise etc. (e.g. I’m going on holiday next week.) We can also say ‘go to a place for a holiday/ for my holiday (s)‘ (e.g. Steve has gone to France for a holiday.)
a. on television/ on the radio; on the phone/ telephone; (be/ go) on strike; (be/go) on a diet; (be) on fire; on the whole (= in general); on purpose (= intentionally) (e.g. I’m sorry. I didn’t mean to annoy. I didn’t do it on purpose.)