1. Je t'aime. This means 'I love you' - it's a present tense 2. Je t'ai aimé. This means 'I loved you' - it's the passé composé (the most commonly used past tense in French, especially spoken French) 3. Je ne t'ai pas aimé. This means 'I didn't love you'. It's the negative form of #2

Je t'aime is I love you it's about love

To add a bit more. Je t'aime bien, mais je ne suis pas amoureuse de toi. I LIKE you, but I'm not in love with you. Ça arrive plus souvent!! Dave