- He telephoned the police yesterday.
Conveys the sense that the telephone was used, rather than different medium for communication, such as a personal visit or written (email).
- Can you show me the diamonds?
Emphasizes on the item, the diamond; it can be emerald, sapphire, ruby or what not.
- Paul has gone to the theatre.
Emphasizes that is Paul who went to the theatre, not his brother nor his sister.
- Have you heard that Marcella's won £50,000 on the lottery?
It emphasizes the amount of money that was won.
- I'm not doing anything this evening.
Stressing which part of the day, that the person speaking is not busy.
Are my explanations correct?