The word "frigid" means to be very cold.

To use frigid in a sentence, "The long winters days have been very frigid."

To be exactly the same means to be identical.

To use identical in a sentence, "The twins, Alison and Melissa, looked identical."

Going back and forth means to alternate.

To use alternate in a sentence, "I alternate between wearing dress plants and a skirt to work."

To stop working, or to leave a job for good means to retire.

To use retire in a sentence, "My dad is going to retire this year, and he can't wait to sleep-in every day!"