The indefinite pronoun "everything" is always singular. Indefinite pronouns beginning with "every-", "any-", "some-" and "no-" are always singular: everyone, everybody, everything anyone, anybody, anything someone, somebody, something no one, nobody, nothing With "everything", the meaning is literally "every (individual) thing". The salad was delicious. The soup was delicious. The steak was delicious. The asparagus was delicious. The dessert was delicious. Therefore, each thing (or "every thing") was delicious -- one by one.

'everything': ONE situation, singular: was 'all presents': SEVERAL presents, plural: were