This document discusses the differences between the -ing form and the infinitive form of verbs in English. It notes that certain verbs are followed by the infinitive, such as "forget", "help", and "teach". Other verbs are followed by the -ing form, like "avoid", "dislike", and "enjoy". The -ing form is also used after prepositions. Some verbs can be followed by either the -ing form or infinitive without changing the meaning, while for other verbs the form changes the intended meaning.