Maybe I missed this in the tips section, but why is it "בכם" and not "לכם?"
It's just the way the verb תמך works. It takes the preposition ב.
How can you tell which verbs need the preposition "ב"? Is there a rule or a list to remember?
What verb is תמך?
It's the basic form of the verb תומכים, it means "support". It always goes with ב.
ל = to
ב = in, at
תמך בכם = support in you
ha-gvarím tomchím ba-chém.
If this is בכם, why is this "you" and not "them"? Shouldn't "you" be בך?
Bachem is the plural "in you", if you want to say "in them" it would be "bahem"
'Bachem' is from 'atem' so it should be them and not you