Finishing off with the last three.
Gifts - this is someone who enjoys giving and receiving. And it doesn't have to be something big. A simple card, a bagel from the shop, one flower - those all count big time. A person whose love language is gifts will go nuts everytime you give them something or leave a little something for them to find later. This makes them feel loved - and by giving gifts to you, that is how they express love.
Acts of Service - just as it implies. It is not 'giving' something, but 'doing' something for someone. Like washing someone's car, cleaning the house, fixing a leak in a pipe - those are all loving acts of service. So is getting the car door for a woman or having a great meal prepared when a man comes home.
Quality Time - I've been over this one before, because it's the one I struggle with! Quality time is sharing moments together, either playing a game, going to an event, or just sitting and talking. It helps if the moment is very interactive, but even curled up together on the couch watching a movie can mean a lot to someone who needs quality time. They enjoy the presence of others.
Now the real trick - what love language do the people you care about speak?
If you express an act of love that is designed for the other person's benefit or pleasure, it is simply a choice. Gary Chapman "The Five Love Languages"