Struggling with phrasal verbs? Just call on Tim Bowen.
‘Search and rescue teams combed the area for several hours but there was no sign of the missing yachtsman and the search was called off as darkness fell’. In this context, call off means to decide to abandon an activity that is already in progress, but it is also possible to call something off before it starts, especially an event such as a wedding, a meeting or a match, as in ‘The pitch was waterlogged and the game was called off shortly before two o’clock’.
Often used in the passive, to call on means to make an official or formal request for someone to do something, as in ‘UN troops are being called on to act as peacekeepers in the troubled region’ or ‘The petition calls on the government to do more to preserve rural bus services’.
If you call out a particular service, you ask a person or organisation that provides that service to come and deal with something for you, as in ‘If you call out the engineer, they charge you £55’. The fee in question in that situation is a call-out charge.
Both to call round or call by are used intransitively to mean ‘to visit someone in their home’, as in ‘Why don’t you call by next time you’re in this part of town?’ or ‘I called round yesterday but you weren’t in’.
Again often used in the passive, to call up can be used to officially tell someone they have to join the armed services, especially in a time of war, as in ‘To avoid being called up, many young Americans made their way across the border into Canada’.