The most important things are hardest to say. Words matters the most. It is a big event so choose your words accordingly. Proposing her by saying “I Love You” is a traditional way. The more you improvise your success rate increases. “Do you want to spend rest of your life with me?, “Let’s spend the rest of our lives together”, “I want to grow old with you”, “ Will you make me the happiest man alive?”. These are some of the lines can be used for proposing her. These words show deep emotions and feelings for her. Practice these formulas before proposing your girlfriend. You can also try some of the propose a girl lines.