In Japanese the word for love is ai (愛). There are different ways you can say I love you in Japanese. Ai is a very strong word with lots of meaning.
Love you = anata o aishite imasu (あなたを愛しています)
Love mom = okaasan o aishite imasu (お母さんを愛しています)
Love you (casual) = aishiteru (愛してる)
In a previous lesson we learned the word suki which means to like. In Japanese you will see suki used to mean love. It can be used for people, animals, objects and anything else. In sentences like the ones below, desu can be added to make the conversation more polite.
Like/love = suki (好き)
Really like = daisuki (大好き)
I like reading books = hon o yomu koto ga suki desu
Often you will see no koto added. This usually is to emphasize things about something. When it is used on a person it often shows that you are referring to them as a whole.
When Japanese people tell someone they love them it is called one of the verbs below.
To confess = kokuhaku suru (告白する)
To be confessed to = kokuhaku sareru (告白される)
I confessed to her = kanojo ni kokuhaku shita (彼女に告白した)
When someone hits (flirts) on someone else, the verb kudoku is used.
He hit on me = kare ni kudokareta (彼に口説かれた)
I hit on her = kanojo o kudoita (彼女を口説いた)
In Japanese kare/kareshi can be used for the word boyfriend. kanojo can be used for the word girlfriend.
Do you have a girlfriend = kanojo iru no (彼女いるの)
Have a girlfriend = kanojo ga imasu (女がいます)
Ex boyfriend = moto kare (元カレ)
Ex girlfriend = moto kano (元カノ)
Another term that is used for the word love is koi which is used similar to ai but is only used for romantic love.
Lover(having a affair) = aijin (愛人)
Loved one = koibito (恋人)
Couple = koibito doushi (恋人同士)
First love = hatsukoi (初恋)
Other related phrases
Will you go out with me (polite) = watashi to otsukiai shite kudasai (私とお付き合いして下さい)
Will you go out with me = watashi to tsukiatte kudasai