Three Common Mistakes with Apostrophes Apostrophes are responsible for some serious writing errors. Here are the three most common mistakes related to apostrophes: (1) To show normal plurals. three cat's (should be "cats") good idea's (should be "ideas") two video's (should be "videos") (2) Randomly before the letter "s."

One of the most common mistakes people make with apostrophes is using them incorrectly for plurals. Remember, the apostrophe is not used to make a word plural. Instead, you simply add an “s” to the end of the word. For example: Dogs (not dog’s) Apples (not apple’s) Cars (not car’s)

Similarly, apostrophes are not needed in abbreviations like DVDs or HGVs. This same rule also applies when using numbers like the 1920s or the over 60s. Another common mistake is forgetting that the contractions 'should’ve', 'would’ve' and 'could’ve' are shortened versions of 'should have', 'would have' and 'could have'.