How to tell if someone likes you in an email.

They'll usually write longer messages, not shorter ones.

What would prevent you from asking the person directly? I would appreciate if anyone told me that the person romantically or platonically like me, as long as they don't force me to reciprocate if I couldn't. It is a positive emotion, so please don't feel embarrassed. If yes, happy ending; in case, no. it is time to move on.

Mind-reading is not entirely impossible. But without knowing the gender, the character, and other necessary info, it is impossible for us to truly tell you. There are psychological differences between different genders, among characters, individuals etc.

I have anxiety to ask the guy if he likes me since if he doesn't then I will be sad. I have been sad for awhile already. I don't want to be sad anymore I think.

1) Let's double check together the following if they are facts.
a) You are sad because you don't know the feeling of the person.
b) You're going to continue being sad if you still don't know. In other words, you're unable to get rid of your sadness unless the person confirms he/she likes /loves you.

2) What will the outcome be if you ask the person?
A) The person admits he/she loves you, you are happy. The chance is 50%. Your life changes, you are not going to be as sad as now.
B) The person tells you he/she doesn't you, you are sad. The Chance is 50%, but what's the difference between without asking him and asking him? If so, it is same you will be as sad as now.

There is 50% of the chance that you can be happy, but you don't want; you actually choose 100% being sad all the time.

What is the worse if the person turns you down? You would be very sad for a while, but you are going to have other options instead of being stuck with the current situation. For the options, I refer to you can find other people who you love and would like to love you reciprocally.

Thanks. I think I will try ask the person if he is interested. I just have anxiety that no one wants to be with someone quiet like me. I wonder if that makes sense though.