The word "concerned" always bothers me. I don't know how to use it properly and I looked into the dictionary many times but still couldn't get it. I'd like to give several examples.
I always think about whether my mother, who lives alone, is eating properly. In this situation, can I say "I'm concerned about what my mother eats."?
When I'm with other people, I tend to think that they are doing all right or everything is all right with them all the time. In this case, can I say "I'm concerned about others a lot."?
I'm taking an important test tomorrow. In this case, can I say "I'm concerned about my test for tomorrow."?
Please tell me whether there are more appropriate sentences for these situations.