Adding onto what Tinkeringbell said, some people will assume that if someone of the opposite gender asks them to dinner, or a movie, or coffee, or some other date-like activity, alone, that that implies the activity will be a date. However, most will not!
In my experience, whenever I ask someone out of the same gender, I try to explicitly state that it will be a date, usually by using the word 'date'.
There's two ways to do this, either start by asking them out and then include a specific suggestion:
"Hey, do you want to go on a date sometime? I was thinking we could go to [insert fun thing here]"
Or, if you're already friends with them and you'd want to go do the thing anyway, regardless of whether or not it's a date,
"I was thinking of going to [insert fun thing here], do you want to come? It could be a date! Or not, if you'd rather just go as friends."
I often forget to do this when asking out someone of the opposite gender, since I assume they will assume it's a date (and you know what they say about when you assume, it makes an a** out of u and me). This can often lead to confusion since you just ask "Hey, want to go do [insert fun thing] with me?" leading to the other person asking "What, as a date, or...?" This is awkward, especially if their answer is no! So, always clarify, and good luck!
