Hi, Aga - "rely on" works well in this sentence, but you could also say, Students can always count on their families. Hope that helps! heather

More examples: "Students can always lean on their families" "Students can always depend on their families" "Students can always look to their families for support"

Some other related expressions. - to rely on = to depend on = to count on. - to get help/support from (their families). - to look to (their families) for help/support.

I'm not sure there is any rule that says phrasal verbs are less formal. I think formality is still on a case by case basis. . As Heather says "rely on" and "count on" are similar. "Count on" beiung somewhat less formal. . Students can always lean on their families. - slightly different meaning, but similar. . I think whether or not students can rely on families is a culturally-dependent thing.