How do you know that you are ace?

Asexuality is a spectrum and you can still have "the one" while being ace. Some ace people do not experience different types of attraction. For example, asexual people do not experience sexual attraction, and some do not experience romantic attraction. It is possible to be ace whilst experiencing other forms or attraction.

How does being ace affect your dating life?

Sexual intercourse is not the main point of a relationship. Ace people can still be in relationships and have that romantic intimacy with their partners without having sex. The bond in relationships is way more stronger to ace people rather than having sex or physical intimacy.

Can you be aromantic and still desire a relationship? Can you still fall in love?

Yes you can! You can still desire a relationship because you can have sexual attraction to your partner(s) and not have any romantic attraction, which is not a bad thing! As long as you are comfortable and your partner(s) are comfortable as well. On the subject of falling in love, you can fall in love. Aromantic people experience love in a non romantic way, such as friendships,family, and or platonic. Whilst, some aromantic people do not experience feelings of love at all but that doesn't mean they don't have any sense of care in their heart.