The main task of the semicolon is to mark a break that is stronger than a comma but not as final as a full stop. - This is a good definition I found (http://www.oxforddictionaries.com/words/semicolon). Simple examples: (Taken from: http://grammar.about.com/od/rs/g/semicolonterm.htm) - "A banana tree isn't a tree at all; it's the world's largest herb." - "Happiness isn't something you experience; it's something you remember." - "Management is doing things right; leadership is doing the right things." Examples: (Taken from: http://www.bbc.co.uk/worldservice/learningenglish/grammar/learnit/learnitv55.shtml). Where the meaning is closely connected, we can use semi-colons to link two ideas together as an alternative to full stops: 'Some people like to get up early in the morning and get going; others are unable to do anything before nine or ten o’ clock.' Like commas, semi-colons are also used to separate items on a list and are preferred to commas when the items are more grammatically complex: 'You can use our flat at the seaside as long as you observe the following: you do not play loud music late at night; you remember to lock up whenever you leave; you clean up every morning before you go out; you replace any items that you break or damage.' Finally... "Unlike many of the other punctuation marks, there is no occasion on which the semicolon cannot be replaced by another form of punctuation or sentence construction, and its use appears to be gradually declining." (Martin H. Manser, Good Word Guide, 7th ed. A & C Black, 2008 Probably a little bit more than you asked for, but I hope ti answers all your questions about it.

English is very difficult; however, you can learn it if you study hard. He was very rude to me; therefore, I no longer speak to him. This job is very difficult; nevertheless, I absolutely love it.