What are the common errors when forming contractions?

1. Misusing the apostrophe. The apostrophe in a contraction replaces the missing letters, not the "s." For example, " it's" is correct, but "its" is incorrect.

2. Using the wrong form of the verb. The verb in a contraction must be in the correct tense and form. For example, "I've" is correct, but "I have" is incorrect.

3. Using a contraction in the wrong context. Some contractions are informal and should only be used in casual writing or speaking. For example, "I'll" is informal, but "I will" is more formal.

4. Using a contraction with a possessive pronoun. Possessive pronouns already indicate ownership, so they should not be used with an apostrophe. For example, "your's" is incorrect, but "yours" is correct.

5. Using a contraction with a plural noun. Plural nouns already indicate more than one, so they should not be used with an apostrophe. For example, "book's" is incorrect, but "books" is correct.