We are initially (taught) to love.
If someone smiled and insulted you in their native foreign language you wouldn't be upset (because you haven't been taught) that it's an insult. Therefore there is no link between the words and emotion until you learn to connect them. Giving meaning to words elicits emotional connections to them.
For many of us it starts with us being (told) by our parents to say "I love you" to our grandparents and other family members at a very young age. During our infancy it's all about being "self-centered".
It's not uncommon to overhear a parent in the background (coaching) their 3 year old child who is talking on the phone to say; "I love you grandma or I love you grandpa".
Clearly that child has no idea what that statement means!!! Nevertheless he or she (learns) that it "pleases people" when they say it. They also often get some type of reward or acts of kindness in return. This (encourages) them to use the word more often.
As we grow older we learn about romantic love through books, poems, and movies. Others also (tell us) what it means to be "in love" and how to tell if someone else loves us based upon the way they treat us.
A person may feel like they can't stop thinking about someone and they want to be with them everyday or can't imagine not having them in their life. The self diagnosis is "I'm in love!"
We're taught the word "love" encompasses all of those feelings.
Having said that I imagine if someone were born on a island with no outside influences and they befriended an animal whom they spent years playing with only one day to find it dead.
I imagine he or she would be overcome with grief. And although they were never "taught to love" the pain they would be feeling for their loss would be the result of having loved.
In some respects you can't teach a person feelings/emotions but they come to learn how to describe what they're feeling with words such as love, happiness, sadness, or anger.