Contractions

1. Contractions are shortened forms of single words from which the middle is omitted, e. g. Mr., Dr., as opposed to those in which the end is omitted, e.g. Prof., Rev. Commonwealth style tends not to use a full stop when letters are omitted from the middle of a word, e.g. Mr and Dr

2. Contractions are also telescoped phrases such as don’t, I’ll, there’s we’ve. In all such cases, the apostrophe marks the place where a letter or letters have been omitted.