How do I say "...." in Japanese?
How do I say, "I Love you"
- 愛している Aishiteiru
Can be said just on its own or as (name) を愛している
Is a very strong I love you. It would be the kind of "I love you" that would be said in a highly emotionaly charged moment.
- 好きだ suki da
A stronger version is 大好きだ. It can be said on its own or as (name) が好きだ.
This is more of a romantic love, still not used as casually as we do in English speaking countries. Note that this is exactly the same as the phrase used to say you like manga or other things (まんががすきです。manga ga suki desu.)
How do I say, "You are pretty"
- きれいだ kirei da
How do I say my name in Japanese?
Names are spoken according to the closest Japanese approximation of the native pronunciation, not the native spelling. Thus, only people who know how to pronounce your name correctly can give you the correct Japanese spelling or pronunciation.
How do I write my name in Japanese?
Just as names are spoken according they are written in kana based on the name's pronunciation. Foreign names are written in katakana and native names are written in Japanese. There is a good list of common names with standard transliterations at Takase.com
Please keep in mind that kanji like letters, are generally put into specific combinations to produce words. Often foreigners will combine kanji with desired meaning, the result; however, rarely a combination of meanings but gibberish. Even combining kanji based on pronunciation and not meaning will not work unless the result is a dictionary word. If you want to write your name in Japanese, avoid Kanji unless you happen to have a Japanese name. Write your name in katakana.
If considering getting a kanji tattoo don't forget that China uses hanzi which are the origin of kanji. However a kanji will be read in Japanese might mean something completly different to a Chinese speaker.