15/06/2010 | jiangws2002 increase a)noun: 1. When you are talking about a thing that has increased, the most usual preposition to use after increase is in . Don’t say ‘an increase of something’, say an increase in something : There has been a 2% increase in the rate of unemployment. 2. Remember: when increase is followed by an amount, the correct preposition is of : There has been an increase of 2%. b)verb Increase is not usually followed by the adverb ‘up’. Don’t say ‘increase up’, say increase : The number of homeless people has increased up by 5%. The number of homeless people has increased by 5%.