一、经典永恒类

1. "I love three things: the sun, the moon, and you. The sun for the day, the moon for the night, and you forever."

（我爱三样东西：太阳、月亮和你。太阳代表白天，月亮代表夜晚，而你代表永恒。）

2. "I AM YOU. YOU ARE ME. WE ARE ONE."

（我就是你，你就是我，我们是一体。）

3. "I need him like I need the air to breathe."

（我需要他，正如我需要呼吸空气。）

二、未来期许类

1. "Think of being able to accompany you to grow old all the time, I feel that my life is not in vain."

（想象能陪你慢慢变老，我觉得生命不再虚度。）

2. "In the vast sea of people, I cannot stop my love for you."

（在茫茫人海中，我无法停止对你的爱。）

3. "The wings of love have opened, waiting for you to accompany me to take flight."

（爱的翅膀已展开，等待你陪我翱翔未来。）

三、情感共鸣类

1. "Your smile is the sunshine that brightens my whole world."

（你的笑容是我世界的阳光。）

2. "In your eyes, I see the words of last good-bye."

（在你眼中，我读懂了再见。）

3. "Every moment with you is a treasure I will cherish forever."

（与你共度的每一刻都是我永恒的珍宝。）

四、诗意抒情类

1. "Cold here, icy cold there. You belong to neither, leaves have withered. Your face is pale and blue, a tearful smile."

（此地寒冷，彼处更冷。你不属于任何一方，叶子已凋零。你的面容苍白，带着泪光的微笑。）

2. "The world of love burns my heart and makes my life no longer calm."

（爱情的世界燃烧着我的心灵，让我的生活不再平静。）

3. "Smile floating on the lemonade, soft and smooth."

（柠檬水上的微笑，温柔而顺滑。）

使用建议：

可根据具体关系调整语气，亲密关系建议加入对方名字或具体回忆，普通朋友则更适合使用诗意表达。- 若搭配手写信件，可在签名处添加“Forever yours”或“With all my heart”等温馨话语。希望这些模板能帮助你表达真挚情感!