Question

There is several projects that the company hasn't completed successfully find error

Answer 1

There are several projects that the company hasn’t completed successfully

Answer 2

There are several projects that the company hasn't completed successfully.

Explanation:

• In the given question we need to find the error.
• We have changed "is" with "are" because the sentence wants to convey that the company has not completed its several projects which means the sentence depicts a plural noun.
• A plural noun can be easily understood as they end with the letter "s" after the name of the noun. But there are some exceptions like scissors, trousers, hundreds, etc.
• With plural noun "is" is not used rather "are" is used.