How to use "substantially"

What Does "substantially" Mean?

• What it expresses: It primarily expresses degree or extent, indicating that something is true to a large, considerable, or significant degree. It can also imply approximation in legal or technical contexts (e.g., "substantially the same").
• What part of the sentence it typically modifies: It most frequently modifies verbs (substantially increase), adjectives (substantially higher), and occasionally past participles used as adjectives (substantially improved).
• Register: It is a formal to neutral adverb. It is highly prevalent in academic, legal, financial, and journalistic writing, but less common in casual, everyday conversation.

How to Use It

• Typical sentence positions: The most natural position is mid-position, specifically before the main verb or after the first auxiliary verb. It can also appear in the final position for emphasis, though this is less common. Initial position is rare and usually only used when modifying a whole clause for rhetorical effect.
• What it modifies and how it changes the meaning: When it modifies a verb like "increase" or "change," it quantifies the action as being large enough to be important. When modifying an adjective like "different," it emphasizes a major gap between two states.
• Grammatical flexibility: It works well with negation (e.g., "not substantially different") and in questions, though it is more frequent in declarative statements. It is often used in comparative structures (e.g., "substantially more than").
• What sounds unnatural or incorrect: Using it to describe simple physical size in a casual context (e.g., "I bought a substantially big apple") sounds stilted. It should be reserved for describing changes, differences, or impacts.

Real-World Examples

These examples are sourced from substantially on Ludwig.guru.

"Today he had to admit that not only has he missed his debt target but that growth will be substantially lower than he forecast." — theguardian.com

"The troubled broadcaster, which suffered the dreaded zero audience rating for some of its shows after its launch on 31 March this year, was told by on Ofcom on Tuesday that the proposals were "significant variations" which would "substantially alter" its output." — theguardian.com

"They found a strong relationship between the outgoing long wavelength radiation (infrared energy) and temperature; however, this relationship varies substantially across the planet." — theguardian.com

"AOn Wednesday, colleagues of Daly will present a substantially identical resolution on greenhouse gas emissions at a shareholder meeting convened by fellow oil company Chevron." — theguardian.com

"The law would prohibit state and local laws that "substantially burden" the ability of people – including businesses and associations – to follow their religious beliefs." — theguardian.com

Examples sourced from https://ludwig.guru/s/substantially

Similar Phrases and Alternatives

Phrase	Context
considerably	Highly similar; used to describe a large enough amount to be noticed.
significantly	Often used in statistical or scientific contexts to denote importance.
largely	Shorter and more neutral; works in both spoken and written registers.
to a great extent	More formal; typically used in academic or analytical writing.
materially	Specific to legal and financial contexts, meaning to a relevant or important degree.
vastly	Suggests an even greater degree than substantially; more emphatic.

Common Mistakes

• Wrong Scope: Using it to mean "essentially" in a casual way. While it can mean "in essence" in legal terms (substantially the same), in general English, it should focus on the degree of change or difference.
• Register Mismatch: Using it in informal texting or casual conversation (e.g., "I'm substantially hungry") can make the speaker sound overly robotic or pretentious.
• Learners often confuse it with 'considerably' or 'significantly' in contexts of physical size, failing to recognize its specific use in formal or legal registers to denote 'to a large degree'. For example, while a building is "considerably tall," a contract is "substantially complete."

Quick-Reference Summary

Expression	Function	Register	Typical Position
substantially	Degree / Extent	Formal / Neutral	Mid-position (before verb)

FAQs

Where should I place substantially in a sentence for the best flow?

The most natural placement for substantially is in the mid-position, situated directly before the main verb or after an auxiliary verb. Placing it at the end of a sentence is acceptable for emphasis, but the initial position should generally be avoided unless you are modifying an entire clause.

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How does substantially differ from significantly?

While both denote a large degree, significantly often implies that a change is meaningful or has a specific cause, frequently used in statistical contexts. In contrast, substantially emphasizes the volume or extent of the difference and is the preferred choice in legal or financial registers to describe the weight of a change.

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Can I use substantially to describe the size of an object?

Learners often confuse it with considerably or significantly in contexts of physical size, failing to recognize its specific use in formal or legal registers to denote to a large degree. You should use substantially to describe abstract amounts, changes, or qualitative differences rather than the literal dimensions of a physical object.