Other
Oxford Dictionaries: Verb Tenses: Adding Ed and Ing
Spelling rules and word lists for adding -ed and -ing endings to verbs.
Quia
Quia: Inflectional Endings (S, Ed, and Ing)
Decide which inflectional ending matches the verb in each sentence.
PBS
Pbs Learning Media: What Verbals Are
Verbals are verbs disguised as nouns, adjectives, and adverbs. Verbals come in three forms: gerunds, infinitives, and participles. Gerunds are verbs that end in "-ing" and function as nouns. Participles end in "-ing," "-ed," "-d," "-t,"...