To the world you may be one person, but to one person you may be the world．
对于世界而言，你是一个人；但是对于某个人，你是他的整个世界。

Love me little, love me long!
爱不贵亲密，贵长久！

This card is to let you know that I still love you after all of these years.
这张卡片是要让你知道，纵使时光流逝，我却爱你如初。
be动词后可接不定式“to do”结构作表语。

You have been and still are my only true valentine.
从过去到现在，你一直是我惟一真正爱恋的人。
valentine n.情人

On this Valentine's Day, just like every day all I have is love for you.
如同每一个平常的日子，我在这个情人节里所拥有的东西，就是对你的爱。
Just like every day在这里作插入语，意为“如同每一个平常的日子”。

To my ever loving; I am yours forever.
献给我永远的爱人；我将永远属于你。
loving a. 亲爱的，钟情的

I knew that there would be ups and downs when I married you. But through it ail you have always been my Valentine．
当年娶你，已知人生总有起伏不定的时候。但经历过这一切的甘与苦，你终究是我的爱人。
ups and downs“盛衰，沉浮”

After 15 years, our love is even stronger than before.
15年已经过去，我俩的爱情历久弥坚。

To my one and only Valentine: I love you.
献给我惟一的爱人：我爱你。
one and only“惟一的“

You have always been there for me, and I will always be there for you Happy Valentine's Day.
你永远在那里等待着我，而我也将永远在那里守候着你。情人节愉快。
Happy Valentine's Day. 一般只用于情侣之间的相互问候，不适用于同性之间的问候。

To the girl of my dreams and the mother of our child: you are the only Valentine for me.
献给我梦中的女孩及我们孩子的母亲：你是我惟一的爱人。
介词to可以表示“献给…”。

I will be your Valentine until the end of time．
我将是你的情人，直到地老天荒。
until the end of time“直到地老天荒”

I made the right choice when I decided to marry you. Be my valentine forever.
决定跟你结婚，是正确的选择。愿你今生今世做我的情人。
choice n．选择

No one has ever loved me the way you do. I love being your little Valentine.
从来没有人像你这样地爱我。我喜欢做你的小情人。
ever ad. 曾经，以往，任何时候

I didn't think I could ever trust  happiness. Then I met you.
我一直不相信有真正的“幸福”，直到不久以后，我与你邂逅。
trust v．相信

Our love grows stronger with every passing year. Happy Valentine's Day, baby.
我俩的爱，一年比一年更坚定。亲爱的，情人节快乐。
情人之间亲密的称呼除了本句中的baby之外，还可以说sweet，sweet heart．honey及darling等。

更多英语口语资料