I can say "Jerry's been a bad pussycat this morning" or "Hey, Jerry, you be a good pussycat now" or "Jerry's been active all morning so he's being a good pussycat now". All these involve the use of the verb be.
Now if I said "if Jerry bes a bad pussycat, put him in the laundry," I'll sound ungrammatical. How else can you say this without being specific about the verb? I understand the future tense of to be is is but then it sounds like present tense rather than future tense.
I don't want to say "if Jerry behaves badly" because it's too complex. And I don't want to say "if Jerry is bad" because that implies current state rather than future state.
Should it be "if Jerry would be bad..." or "if Jerry should be bad" perhaps?