alarm sb 使惊恐，使担心
I didn't want to alarm my mom by telling her that I was ill.
我不想让妈妈担心，就没有告诉她我生病的事。

concern sb 使某人担心；让某人担忧
It concerns me that you no longer seem to care about me.
你好像都不在乎我了，这让我感到很担心。
It concerns me that he hasn't been in contact.
还没有联系到他，我很担心。
His attitude concerns me.
他的态度让我很担心。

misgiving about sth/doing sth 疑虑；顾虑
I had grave misgivings about making the trip.
对于这次旅行，我有过极大的顾虑。
My only misgiving is that we might not have enough time to do the job well.
我唯一担心的是我们没有足够的时间把这个工作做好。

pussyfoot 慎重，顾虑重重
Stop pussyfooting around/about and tell me what you really think.
不要顾虑重重的了，告诉我你怎么想的。

hung up on/about sth/sb 十分担忧；想得过多
Don't get hung up on details.
别太担心细节。
You shouldn't get hung up, man.
别再为这事闹心了。
Why are so many women so hung up about food?
为什么女性都这么担心饮食。

cry over spilled milk 作于事无补的担忧，为无可挽回的事忧伤
Well, there's no use crying over spilled milk.
事已至此，担心也没有用了。