substantially

substantially — adverb

1. by a wide margin in terms of amount, size, or effect — used when a change, diffe

1.adverbB2
Definition

by a wide margin in terms of amount, size, or effect — used when a change, difference, or improvement is big enough to matter.

Example

Energy costs have risen substantially across the northern states this winter.

verb + substantially (change verb)

Tanvi's reading speed improved substantially after she started practising every morning.

substantially + past participle

Common collocations
  • increase substantially
  • reduce substantially
  • differ substantially
  • substantially higher/lower
  • substantially greater
Synonyms
  • significantly

    very similar, but slightly more formal and often used in statistics or research

  • considerably

    almost interchangeable; slightly weaker in suggesting a noticeable degree

  • greatly

    strong but more emotional; common with feelings and appreciation

  • markedly

    more formal, used when the change is clearly visible or measurable

Antonyms

Grammar Patterns

substantially + comparative adjective

verb + substantially

substantially + past participle

Usage Note

Commonly appears with verbs of change (increase, reduce, improve, differ) and with comparative adjectives (larger, smaller, higher, lower). Stronger than 'moderately' but less specific than a precise number.

Common Mistakes

The price raised substantially.
The price rose substantially.
use 'rise', 'increase', or 'grow' with substantially, not the transitive 'raise' unless you name an agent.

2. in the main ways that matter most, even if minor details are not identical — use

2.adverbC1
Definition

in the main ways that matter most, even if minor details are not identical — used when comparing two things that are alike in their core features.

Example

The two novels tell substantially the same story, although the endings differ.

substantially the same

Alessia said the report was substantially accurate, aside from a few minor typos.

substantially + adjective of accuracy

Common collocations
  • substantially the same
  • substantially correct
  • substantially unchanged
  • substantially similar
Synonyms
  • largely

    interchangeable in most contexts; slightly less formal

  • broadly

    focuses on the wide scope of agreement rather than the core

  • mostly

    more informal and everyday; implies more exceptions

  • for the most part

    phrase equivalent; more conversational rhythm

Antonyms
  • completely

    totally identical in every detail, not just the main points

  • entirely

    no exceptions; opposite of 'almost but not quite'

Grammar Patterns

substantially + the same/similar/correct/unchanged

substantially + adjective of agreement

Usage Note

Distinguish from sense 1: sense 2 talks about the degree of ALIGNMENT between two things, not the size of a change. It pairs naturally with words like 'same', 'correct', 'unchanged', 'similar'. This sense is not used with comparative adjectives ('higher', 'lower').

Common Mistakes

The temperature is substantially the same as yesterday.
The temperature is roughly the same as yesterday.
'substantially same' works for complex ideas or texts, not for simple physical measurements.

Word family

Synonym discussion

Sense: adverb/1

All five adverbs describe a large degree of change or difference, but they differ in tone and typical context. Substantially is the most neutral and versatile of the group — it works in business reports, everyday speech, and academic writing without sounding out of place. Significantly carries an implication that the change is important enough to notice or measure, making it the preferred choice in research papers and data analysis. Considerably is slightly milder: it suggests a noticeable gap but one that might not be decisive. Greatly is the most emotional of the group — people use it with feelings ('greatly appreciate', 'greatly relieved') rather than with objective numbers. Markedly is the most formal and descriptive, used when a change is plainly visible. For example: 'Sales increased substantially after the campaign' (neutral fact); 'The treatment significantly reduced patient symptoms' (research finding); 'She was greatly encouraged by the news' (emotional impact); 'The temperature dropped markedly at sunset' (observable shift).

substantially ↗significantly ↗considerably ↗greatly ↗markedly

Common collocations

Adverbs

  • very substantially
  • quite substantially

Phrases

  • increase substantially
  • reduce substantially
  • differ substantially
  • substantially the same
  • substantially correct
  • substantially unchanged

Etymology

LatinFrenchEnglish

The adverb 'substantially' was formed in English around the 1600s by adding the adverbial suffix '-ly' to the adjective 'substantial'. 'Substantial' itself came from the Latin word 'substantialis', meaning 'pertaining to the essence or substance of something', which in turn came from 'substantia' ('substance, essence, being'). The earliest English use carried the meaning 'in a real or actual manner', but by the 1700s it had split into the two modern senses: one about large quantity and one about core agreement.