Alice: I [lost my job,was fired].
Bob: Oh, that’s too bad!
Alice: We didn't make it in time.
Bob: That’s a shame!
Alice: We didn't make it in time.
Bob: That’s a bummer!(slang)
Alice: My [fish, cat, dog, plants] died.
Bob: What a pity! I'm sorry! (rarely used)
Alice: We didn't get the contract.
Bob: How disappointing!
Alice: I didn't get my salary!
Bob: That's bad news!
Alice: I didn't get my salary!
Bob: That's awful!
Ann: I don't think we will make it to your party.
Bob: I'm really disappointed!
Ann: We won't be able to go skiing.
Bob: What a let-down!
Ann: We won't be able to go skiing.
Bob: That's really disappointing because I just bought new skis and I wanted to try them out!
Ann: Our [son,daughter] won't be able to join us.
Bob: This is a let-down!
(How _could_ she let-us down like that?)
(Why _would_ she let-us down like that?)
(Why _did_ she let-us down like that?)
Ann: Our [son,daughter] won't be able to join us.
Bob: I'm disappointed.
Ann: We can't afford the vacation.
Bob: This a [real,major, total] let-down!
Ann:I can't pay you back.
Bob:I'm not [pleased, happy] about this!
Ann: I broke a bottle of bleach in the hallway.
Bob: What a disaster!
Ann: How did you feel afterwards?
Bob: To be honest, I was a bit disappointed.
Ann: How was the show?
Bob: [It,That] was such a disappointment! They were late and performed poorly.
Ann: How's your trip?
Bob: I had high hopes for this vacation. But, I can see that it's going badly already.
Ann: Can you finish this task today?
Bob: I had high hopes that I wouldn't have to work anymore today! I'm leaving at five o'clock. So, no, I won't be able to finish the task.
Ann:
Bob: I had high hopes that we would be in the mountains by now.
Ann:
Bob: I had high hopes that we would own our own car by now.
Ann: Did you hear that Dave was selected as the new manager?
Bob: I really hoped I'd be selected.
Ann:
Bob: I was convinced that I would make the team.
Ann: Did you get the job?
Bob: I was convinced that I would get the job. But I didn't!
I was convinced that the code was good!
I was convinced that the job was done!
What an experience! I wish someone had warned me in advance!
I wish/if only I had been better prepared (for the exam/interview/competition...).
I wish I had worked harder.
I wish I had had more time to prepare.
If only I had listened to ...
I’ve never been so disappointed in my whole life!
That really didn’t live up to expectations, did it?
It wasn’t as good as I thought it would be.
It wasn't all it was cracked up to be!(idiomatic)
Alice: How was it?
Bob: It wasn't all that good.
Alice:How was it?
Bob:It sucked!(very informal)
It wasn’t at all what we had been led to expect.
I was so looking forward to it. What a let-down!
Alice:What's wrong? You don't look happy.
Bob:I was so looking forward to a day off! But they called me back in to work! I'm so disappointed.
[He,It, They] promised more than [he,it,they] delivered.
It was an absolute waste of money.
It was a total waste of money.
I left before the end of the [concert, play, show, opera, party]. It was total [trash, rubbish,garbage]!
The whole thing bored me to tears!
Well, frankly, the event turned out to be a cold blanket!