Substitution

Language Analysis

Substitution is a cohesive device in which one linguistic element is replaced by a pro-form — a word that stands in for a longer expression recoverable from the context. Halliday and Hasan (1976) identified it alongside reference, Ellipsis, conjunction, and Lexical Cohesion as one of the five major types of Cohesion.

Types of Substitution

Nominal Substitution

One / ones replaces a noun or noun phrase:

I like this shirt but I'll take that one.
These cakes are good. Try the chocolate ones.

Same can also serve as nominal substitute: I'll have the same.

Verbal Substitution

Do / does / did replaces a verb phrase:

She works harder than I do.
Did he finish? — He might have done. (British English)

Clausal Substitution

So and not replace entire clauses:

Will it rain? — I think so. / I hope not.
She passed the exam, and I think her sister did so too.

Substitution vs Reference

Both substitution and reference (Anaphora and Cataphora) point back to something in the text, but they differ:

Reference (pronouns, demonstratives): the pro-form refers to the same entity — John came in. He sat down. (he = John)
Substitution: the pro-form replaces a linguistic item but may refer to a different instance — I need a pen. Can you lend me one? (one ≠ the same pen; it replaces the word pen)

Teaching Implications

Substitution is underused by L2 learners, who tend to repeat full noun phrases or verb phrases where a native speaker would substitute. Teaching substitution alongside Ellipsis helps learners produce more cohesive, natural text.

Common errors include:

Overuse of it where one is needed: *I lost my pen. Can you lend me it? (should be one — different pen)
Omitting do so in formal writing: The experiment was repeated as Smith had done previously
Confusion with so and not in clausal substitution: knowing which verbs take so (think, believe, hope, suppose) and which take not (hope not vs don't think so)