There is/are & There was/were (6ºA)

Present:
There is are was were( is, are, was, were ) a pen on the table.

Present:
is are was were( is, are, was, were ) there a pen on the table?

Present:
There isn't aren't wasn't weren't( isn't, aren't, wasn't, weren't ) a pen on the table.

Past:
There was were is are( was, were, is, are ) a pen on the table yesterday.

Past:
There wasn't weren't isn't aren't( wasn't, weren't, isn't, aren't ) a pen on the table yesterday.

Past:
was were are is( was, were, are, is ) there a pen on the table yesterday.

There are is were was( are, is, were, was ) thirty students in my class.

There are is were was( are, is, were, was ) some book in my bag.

There are is were was( are, is, were, was ) some computers on the library.

There isn’t aren't are is( isn’t, aren't, are, is ) any apple on the table.