figure out - determine; reason out by thinking
fill in for -take another’s place
fill sb.in - tell what sb. should know
fish out of water - out of one’s element or natural environment
flying colors -success,victory
for good - permanently; forever
for the time being - for now; temporarily
get away with - escape without punishment
get rid of - give something away; sell, destroy, or throw away something
get the ball rolling - start something; make a beginning
get the hang of - understand; learn
give a hand - help
go without saying - understood; clear without needing to be stated
go off -begin to ring
hang on - keep hold of; persevere;keep doing something
hard to come by - difficult to obtain
have a heart - have kind feelings; be understanding
have a hunch - have an idea based on feelings rather than reason
hold off - delay;postpone
hop to it - get started on something quickly
hit it off - get along well with someone
ill at ease - uncomfortable
in hot water - in trouble
in the air -uncertain