Back to Back

Back is used to indicate a return to a time or place.For that reason, back is used most often with "to go" and "to come." However, it may be used with other verbs related to movement, travel, jobs and relationships. You may also say "to be back," which is the condition of returning from a place. The examples follow and they're self-explanatory.

To Be
#1) We are going to the United States tomorrow and we will be back in two weeks.
#2) My husband left three hours ago to buy milk and he isn't back yet.
#3) When I'm back from my trip, I will call you.
#4) I heard that Tom and Sally are back together. (return to a relationship)
#5) How does it feel to be back? It's good to be back.

To Go
#1) I loved Holland and I plan to go back next Summer.
#2) She will go back to her hometown to care for her sick mother.
#3) I forgot my textbook, so I have to go back to school.
#4) Marie went back to her old job because they offered her more money. (return to a job)
#5) I will never go back to my husband. (return to a relationship/marriage)
#6) I wish I could go back in time and change the past.

To Come
#1) I'm leaving now, but I will come back in an hour.
#2) My roommate came back very late last night and he wasn't alone.
#3) Come back! I'm so lonely without you. (return to a relationship)
#4) I asked for my job back, but they said that there's no job to come back to. (return to a job)

Other
#1) Welcome back! How was your trip?
#2) Get back in line! (military / school / prison expression)
#3) He lent me his car and he took it back the next day.
#4) Stay back! I will jump off this building. (Don't come closer to me! -- suicide expression)
#5) We had to walk back home because our car broke down.
#6) I take back everything I said. (I said something, but I want to un-say it.)
#7) We drove around the city for two hours before we turned back.
#8) Give me back my guitar!