Fall – phrasal verb

Fall behind – fail to keep level with

After running 3 miles he started to fall behind the rest of the group.

Fall for – to be tricked into believing a lie

I can’t believe she has fallen for this blatant lie.

Fall in with – to agree to something

We all fell in with his proposals.

Fall out with somebody – have an argument and no longer be friends

I fell out with him over his opinions on politics.

Fall through – to fail to happen

Their holiday plans fell through because of money.

Fall back on – to go to someone for help, to have resources when in trouble

I have some money in the bank to fall back on when the times are tough.