Bonus note from 5:30 AM:
SWBAT means “students will be able to.” It’s how I learned to frame my objectives in TEFL.
It’s a good way to plan lessons because it focuses on what students will be doing and what they’ll be getting out of it.
A string of favorite activities does not make a great lesson if those activities are not to the purpose. And the purpose revolves around what students will be able to do.
Even an inspired explanation of a point in an ESL class is just teacher talk if the lesson never moves on to students using that point.
SWBAT keeps lessons and units and semesters on track.
That is all.
Learning to Teach English 
yeah, I was going to ask what SWBAT meant, thought it was some sort of ESL-specific teaching mode acronym 😉