TYPICAL ERROR She has neumonia.
CORRECTION She has pneumonia.
EXPLANATION Some words have a silent letter (one that we do not pronounce), so it is easy to forget to include them when we write. In pneumonia, for example, the letter p is not sounded when we say the word.
One reason that silent letters exist is that often the words derive from other languages that have a different alphabet and different pronunciation. Pneumonia, for example, is based on a Greek word. As well, many of our words come from older versions of English where words were once pronounced differently. Once the printing press was invented (which happened in 1440), spelling became fairly fixed, even though pronunciation changed.
Which is the silent letter in the following words?