# substantially

/səbˈstænʃəɫi/ (US) · /səbstˈænʃəlˌi/ (UK)

Source: https://englishreference.com/word/substantially
Updated: 2026-06-20

## Senses

### 1. to a large degree

adverb · CEFR B2 · Academic

by a large amount or to a great degree.

For teachers: to a considerable or significant extent; used to quantify a change or difference.

- The price of the house has increased substantially since they bought it last year.
- The new environmental regulations have substantially reduced the volume of industrial waste discharged into the local river system.

Usage: Commonly modifies verbs of change like 'increase', 'decrease', 'improve', or 'differ'.

### 2. mostly or essentially

adverb · CEFR C1 · Formal · Academic

used to say that something is true in the most important ways, even if not in every detail.

For teachers: in essence or in regard to the main points; used when a statement is true for the most part.

- The two reports are substantially the same, with only a few small differences.
- While the wording has been updated for modern readers, the legal principles remain substantially unchanged from the original 19th-century statute.

Usage: Often used before adjectives like 'the same', 'different', or 'unchanged'.

## Examples

- The new laws substantially reduced the cost of living.
- The company's profits grew substantially after they expanded their operations into the international market.
- While the two proposals appear similar at first glance, they differ substantially in how they allocate resources to rural infrastructure projects over the next decade.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.