What is the difference between direct and indirect object pronouns?

In a simple sentence there is a subject (the person/s doing the verb) and an object (the thing that the verb is being done to). For example, "I read the book"- "i" is the subject and "the book" is the object (as it is being read). In a more complex sentence there is an additional object which is affected by the action in the sentence. For example, "I wrote a letter to Sarah" - "Sarah" is the indirect object. If you are unsure as to whether something is direct or indirect, if it has to/for before it (or could have to/for before) then it is indirect. Direct and Indirect object pronouns are used to replace the nouns in a sentence, usually to avoid repetition and to make a conversation/ written piece flow better. Direct Object pronouns:Me - meTe - you (informal)Le, La, Lo - him, her, it, you (formal)Nos - usOs - you (pl, informal)Les, Las, Los - they, you (pl, formal)Indirect Object Pronouns:Me -to/for meTe - to/for you (informal)Le - to/for him, her, it, you (formal)Nos - to/for usOs - to/for you (pl, informal)Les - to/for them, you (pl, formal)