* They are irregular verbs: This means their past tense and past participle forms are not formed by simply adding -ed (e.g., fit - fitted/fit, set - set/set, read - read/read).
* They can be used transitively or intransitively: This means they can be used with a direct object (transitive) or without one (intransitive).
Here are some examples:
Transitive:
* Fit: He fit the key into the lock.
* Set: She set the table for dinner.
* Read: I read the newspaper this morning.
Intransitive:
* Fit: The shirt fits me well.
* Set: The sun set behind the mountains.
* Read: She reads every night before bed.