- Here is the documents needed.
- Here are the documents needed.
Which is grammatically correct and why? My guess would be the second one because of the plural form.
Documents are plural, so the only correct usage is:
This isn't an edge case, so it is simple. Compare
Where the subject is plural, you use are and when it is singular you use is.
I did a google search for both "Here are examples" and "Here is examples". The former got 360,000 search results. The latter got 5,270,000 results. If nothing else, "Here are the documents" is less likely to make the reader do a double take.
As for which is technically correct, I'm unsure. Several sources suggest that words like "Here" and "There" are exceptions and should not be treated as the subjects of sentences, meaning that you're deciding the subject/verb agreement by the plurality of "documents" in this case, so that "are" is correct.
A noun names a thing. The noun determines whether the verb is singular or plural. Here, you have the noun documents. That means the verb must be plural.
Here is a document. (singular) Here are the documents. (plural)
This holds true for all plural nouns. Some nouns are always plural (e.g. clothes) so they require the plural form of the verb.
If you click on the tag labelled plurals, you can read more about it.