Formal:
* J'aime Courtney. (This is the most literal translation and is appropriate for a formal situation.)
* Je suis amoureux(se) de Courtney. (This translates to "I am in love with Courtney" and is more romantic than "J'aime Courtney.")
Informal:
* J'adore Courtney. (This means "I adore Courtney" and is a stronger expression of love.)
* Je suis dingue de Courtney. (This is a very informal way of saying "I'm crazy about Courtney.")
* J'aime beaucoup Courtney. (This translates to "I like Courtney a lot" and is a good option for someone you have a crush on but don't want to be too forward.)
Romantic:
* Je t'aime, Courtney. (This is the most common way to say "I love you" and is very intimate.)
* Tu es l'amour de ma vie. (This translates to "You are the love of my life.")
Important note: In French, "tu" is the informal "you" and "vous" is the formal "you." So, if you are on a first name basis with Courtney, use "tu." If you are not, use "vous."
It's also worth considering the specific context when choosing how to say "I love Courtney" in French. If you're writing a letter, you might use a more formal expression. If you're talking to Courtney face-to-face, you might use a more informal expression.