How can you tell when a guy is interested?
I would say when he goes out of his way to find time here and there to maybe bump in to you, or cross your path. Also if he tries to make you laugh, or compliments you in any way. He will definitely want to know more about you, he may ask you about yourself, or your likes and dislikes, your favorites and such.
When can you tell a guy is losing interest?
Hum probably when he seems to become distant, doesn't talk as much, or tries to keep the conversation short and sweet.
If a guy isn't initiating conversation is that a red flag?
Not necessarily, he could have other things on his mind, or maybe he doesn't want to come on to strong, so he tries to gradually get to know you.
Guys, what do you think is romantic?
Ok I 'm a guy but honestly I think a walk in the park or on the beach, maybe star gazing, a simple picnic like at a park. Maybe going to a theme park together even.
How do guys show they care?
Well they will be sincere, they will listen to you, they will be there for you, encourage you. They may do something you enjoy doing, even though it's not their thing, just to be there with you. Your feelings will truly matter to them, your safety, and well being. They will do little things to compliment you, maybe even buy a gift now and then for you.
I think a lot of this depends on the type of guy he is though to. I myself may find a girl interesting but I really like to seek God's direction when it comes to that. Also I believe the best relationships are built on Christ, and He should be the foundation and center of it. That's just me though