Here are some examples:
* "J'ai oublié la chose que tu m'as demandé de prendre." (I forgot the thing you asked me to take.)
* "La chose la plus importante est de rester calme." (The most important thing is to stay calm.)
* "Je ne sais pas ce que c'est, mais la chose me fait peur." (I don't know what it is, but the thing scares me.)
The meaning of "la chose" will depend on the context in which it is used.