Colon and semi-colon
The semicolon is somewhere between a weak full stop and a strong comma and used to join phrases and sentences without having to use a conjunction (and, but etc.) where the phrases or sentences are thematically linked but independent.
Look at this example.
Many great leaders; Churchill, leader of Britain during the Second World War; Alexander, the great Roman Emperor and general; and Napolean, the brilliant French general, had great strengths of character which were useful when their countries were at war but also great weaknesses which did not serve them so well in times of peace.
Notice how the semicolon works with the comma to enclose the connected phrases while the whole forms one logical sentence.
The colon expands on the sentence that precedes it.
There are many reasons for poor written communication: lack of planning, poor grammar, misuse of punctuation marks and insufficient
He collected a strange assortment of items: bird’s eggs, stamps, bottle tops, string and buttons.
Peter had an eclectic taste in music: latin, jazz, country and western, pop, blues and classical.