After losing my mother last year, even though I was amazed with a lot of support, there were also people who didn't understand how I really felt. Top of that, some were even rude about it. I am going to write a list of things which you shouldn't say to a grieving person.
1) "I know things aren't fine at the moment, but everything will be fine soon"
This is the one thing that grievers don't want to hear, because it is a huge loss which will take a long time to heal. Best thing to say would be "Sorry for your loss, please take care of yourself."
2) "She is with you"
At that time the griever is experiencing nothing but sadness and a huge void. For them at the moment, they feel that dead people just leave, they are nowhere. Sure they are there in spirit, but that doesn't ease the pain.
3) "At least she is in a better place"
Indeed she is no longer suffering and is in peace, but that doesn't mean it will make the pain any different. Best thing to say would be "I am sorry you are suffering."
4) "I know how you feel"
I would understand if it was coming from someone who had also lost a loved one, but if it was coming from someone who hadn't experienced any of it, then it isn't right, because you don't really know how the griever would be feeling. Best thing to say would be "I may not understand your situation, but I am here to listen."
5) "If there is anything, please let me know"
Best thing to say would be "How about I come there? How about I help you with food, water, cleaning etc.?" Or just give a call. Grievers need someone to just be there with them. They are in a state where they can't accept open offers.
6) "You are handling this better than I expected"
It does sound like a motivation but even if that's the case, the griever is still going through struggles to keep up with their life. Best thing to say would "I understand you may not be feeling great, but it's ok."
7) "What are you doing in college? How can you study? You should be at home, crying!"
This I would consider is the worst thing to say to a griever. Sure they lost a loved one, but that doesn't mean one cannot do the things they love. Saying this would actually lower the griever's feelings and self-esteem. Saying this would not help someone move on from this trauma. Sure they may not do their best, but they are trying and they want to do well. Best thing to say would be "Let me know if you need any kind of help in your studies, I want to see you succeed." Because just with a lot of support and understanding, a griever can do really well.
8) "She would have wanted this way"
First of all, how would others know how their loved ones would have wanted the grievers to be? Only the grievers know what their loved ones would have wanted. Enacting the loved one would only make them feel worse. So a suggestion to the grievers, honor them the way you feel they would like, because only you know!
Lastly,
9) "It's been a while, you need to move on and talk about something else"
This is another worst thing to say to a griever. Losing a loved one is a huge trauma which would take a while to heal. There is so much they would have wanted to tell their loved ones, there is so much they would have wanted to spend time with them, but they never got the chance. It won't be easy for them to just move on and talk about something else. So the best thing to say would be "You must really miss he/she. Tell me more about her/him."
My mom's death impacted me a lot. It was first time I felt a loss. I got over deaths of other people quickly, but this one took me a while, I mean I was extremely close to her, so it won't take a while. I faced all of these comments over this period. I know some weren't just sure what to say and they just wanted to help, but these comments weren't really helpful. Though your intention may be right, your comments might unintentionally make things worse. There were some who were really rude, well all I can say is try seeing yourself at their situation, and hope you get peace and better understanding of things. I just felt I should share this list of things, so that you get a clearer idea on what and how to say and what not to say to someone who is grieving for a loved one. To all those who have given me immense support, really want to thank you all!