Ellipsis (leaving words out) and substitution (replacing words with pro-forms) are essential cohesion devices that make English sound natural. Without them, language becomes repetitive and unnatural: "Do you want coffee? Yes, I want coffee" vs "Do you want coffee? Yes, I do."
Types of Ellipsis
Verbal ellipsis: "She can swim but he can't [swim]"
Nominal ellipsis: "I'd like the blue [one], not the red [one]"
Clausal ellipsis: "Are you coming? I hope so [that I am coming]"
Types of Substitution
do/does/did: "She runs faster than I do"
so/not: "Will it rain? I think so / I hope not"
one/ones: "Which shirt? The blue one"
Why It Matters
Students who don't use ellipsis and substitution sound repetitive and unnatural. These features are especially important in conversation, where economy of expression is valued.
Activities
Shorten repetitive dialogues using ellipsis
Complete conversations with appropriate substitution words
Identify what has been omitted in natural dialogue
Compare student writing before and after applying cohesion devices
FAQ
Is ellipsis the same in formal and informal English?
Informal English uses more ellipsis (dropping subjects: "Going to the shop?" instead of "Are you going?"). Formal English allows verbal and clausal ellipsis but maintains subject pronouns.