Thinking about the problem:
start and begin.

Start/begin here

Imagine you are teaching some learners of English on the topic of vocabulary to do with starting: start, begin, commence, etc. To know how to use these words involves not just the dictionary meaning, but also the company each word keeps.

Do you think start/begin/commence are completely interchangeable? That is, could you use any of these words in any situation to do with starting? Think about this for a while!

Are there differences to do with :

1. what kind of texts the word appears in?
2. what can follow the verb?
   For example, They were beginning noticing versus They were beginning to notice
3. what kinds of subjects the verbs take?
   For example, It was beginning to rain versus It was starting to rain

Make a note of any ideas you have about the usage of these words. At the end of the session, look back and see how close you were!