there is/ there are

For singular item:
Is there a banana?
or
Is there a bunch of bananas?

For plural form:

How many bananas are there?

Also, here's an interesting discussion on "is there" vs "are there"
http://ask.metafilter.com/84536/There-is-or-There-are

如果你要問 "how many" 而 "banana" 又係眾數
那就一定要這樣問:
How many bananas are there?
Otherwise, you can ask:
1) Are there any bananas?
2) Is there any banana?
P.S. "Are" & "Is" 分別用於眾數和單數

你可以問:

Is there any banana?
Are there any bananas?
How many bananas are there?
How many banana is there?

所有都OK，至於Is同Are就取決於你的係banana定bananas啦！

is there any banana,

How many banana is there ?