Nice, both these sentences are accepted: "Did the flowers bloom" and "Have the flowers bloomed"
For me, "did the flowers bloom?" was unacceptable.
same. reported it.
Have the flowers bloomed?
We are waiting for the chirping dog to climb the mountain.
What about the hat-selling one?
This sounds like a song lyrics
It reminds me of the ending song from Aku no Hana.
How do you know if it's one flower or severel flowers?
From the sentence itself, you don't. Japanese doesn't specify singular and plural for most nouns, so both need to be acceptable answers.
i answered 'did a flower bloom?'
but the answer is 'did flowers bloom?'
how can i know that when do i use the plural?
"Has the flower blossomed" would make more sense as a native English speaker. Either is correct but "bloomed" doesn't quite sound right for some reason.
can i say " did the flower bloomed?"
No, because "did" is already past tense, so you wouldn't say "bloomed" after it. "Did the flower bloom?" is a grammatically correct sentence.
the kanji is not accepted