One of the easiest ways to differentiate in the classroom is to use centers/stations. I use them regularly in my Spanish classes to review the objectives from each unit. I have students do a self assessment to determine where they are strong and what they need to work on. Then I introduce anywhere between 8 and 12 stations, making it clear what each station covers. They can then determine which stations they want to do. They can move at their own pace, working on the objectives they choose to review. I help them to pace themselves and circulate to answer questions and provide individual direct instruction where necessary. Here are some of the stations I have for sale on Teachers Pay Teachers.
#1: Here is a collection of 8 stations covering introductory vocabulary. At just $2, it is one of my best sellers and best deals!
#2: For just $1.00 you can purchase a set of activities that focuses on the vocabulary for greetings.
#3: Also, for $2.50 you can purchase a set of activities that focuses on just the number vocabulary.