Teaching the use of contractions is a challenge when dealing with students of English as a Second Language, ESL. Native speakers will immediately recognize the meaning of contractions and include them naturally in their speech and writing. For instance the contraction "I'd" in the sentence "I'd thought so", which is a contraction of "I had thought so," presents no problems to native speakers, but can be very confusing to students of English, especially beginners.
Explain the use of contractions as their use appears in the curriculum. There is no need to do a full class on contractions at the beginning of an ESL course, but if you do not explain English contraction forms students may confuse words or misunderstand native speakers. For example, explain the use of common negative contractions, such as "I can't," in the same lesson you teach how to construct negative sentences.
Clarify the difference between general contractions, such as "he's" for "he is" and informal contractions like "gonna" for "going to." Some teachers may think informal contractions are slang and therefore have no place in a classroom, but students need to at least recognize them when they hear them in everyday speech.
Explain to your ESL students the main exceptions to the general contraction rules. For instance, you cannot contract "will not" as "willn't". The correct form is won't.
Listen to television shows and films in English with your ESL students and ask them to listen for contractions. Get them to write down the contractions they hear, identify the words contracted and specify the type of contraction used.
Teach your ESL students that contractions can have several meanings and that often they must decipher the meaning from the context. For example, in the spoken sentence "She'd have gone if she could've," the contraction she'd can mean "she would" or "she had," but the context makes it clear the speaker meant "she would."
Focus especially on the contractions that have a similar sounding possessive pronoun. For instance, they're and their, who's and whose, you're and your can all be very difficult to distinguish for an ESL student.