Nouns

Adjectives - Comparatives and Superlatives

https://learnenglish.britishcouncil.org/english-grammar-reference/comparative-and-superlative-adjectives

Verbs

Articles (a, an or the)

http://www.grammar.cl/Notes/Articles.htm

Apostrophe for Possession (ownership)

https://www.ef.com/wwen/english-resources/english-grammar/forming-possessive/

Useful websites

Dictionary: http://www.dictionary.com/

Synonyms: http://www.thesaurus.com/browse/synonym