Cases of word usage

1) an official order, especially from a law court, demanding that something shall or shall not be done (injunction)

2) an expression of a positive feeling or affirmative statement by using a negative one, as in 'I shall not be sorry when it's over' (litotes)

3) used with 'I' and 'we' as an auxiliary to form the future tense: 'I shall come as soon as I can' (shall)