All of Arnold's dialogue in this movie should be based around variations of that line.
Sarah: Kyle, this is the T-800 that my son sent from the future to raise me. I call him "T."
T-800: (nods) I was sent back.
Kyle: Pleased to meet you, T.
T-800: (nods) I have to go pick up ammunition. But I'll be back.
(T-800 returns five minutes later)
Kyle: Wow, that was fast!
T-800: I said I'd be back.
Sarah: Okay, we've got to get to Cyberdyne and destroy the Skynet system before the T-1000 finds us again.
T-800: (nods) He'll be back.
(The groups sneaks into Cyberdyne and destroys the entire building.)
Sarah: We did it! We destroyed Skynet!
T-800: They'll be back.
Sarah: What?! How do you know?
T-800: Because I was sent back. If Skynet was truly destroyed, I wouldn't be here.
Kyle: So what do we do now?
T-800: We have to go back... to the future.
...TO BE CONTINUED