Is “Hence Why” Grammatically Correct?

The English language is beautifully quirky and constantly evolving, so it’s no surprise that odd phrases like “hence why” make us stop and think. One I’ve personally used in casual writing, and seen others use in conversations or articles, is exactly that. It sounds natural, sure, but “Is ‘Hence Why’ Grammatically Correct?” exists for a reason  –  this phrase doesn’t follow classic grammar rules, and that’s where the dilemma begins.

In real-world examples, tone and context sometimes beat strict textbook precision. So if you’re aiming for clarity, confidence, and smarter word choices, say “hence” or “that’s why”  –  not both.

Understanding the Confusion Behind “Hence Why”

You’ve probably come across sentences like:

“He was late, hence why he missed the meeting.”

At first glance, it sounds fine. You understand the meaning: one thing led to another. But here’s the catch – “hence why” is grammatically redundant.

Many English speakers say it because it feels right. It mimics how we naturally speak when explaining cause and effect. But what works in casual conversation may not pass the grammar test – especially in professional or academic settings.

Why People Use It:

• It sounds formal.
• It mimics phrases like “that’s why.”
• It combines two cause-effect tools: “hence” and “why.”

But combining both is overkill – you don’t need both. It’s like saying “because because.”

Is “Hence Why” Redundant? Let’s Break It Down

Let’s look at the two words in isolation:

Word	Meaning	Function
Hence	“As a result” or “from this”	Adverb
Why	Introduces a reason or explanation	Conjunction/Relative adverb

When you say “hence why,” you’re literally saying:

“As a result, the reason…”

That’s redundant.

Examples of Redundancy:

• “Hence why he left.” = “As a result, the reason he left.” (Redundant)
• “The reason why he left…” = “The reason he reason he left…” (Also redundant)

We call this type of error a tautology – where you repeat the same idea using different words.

Better Alternatives:

• “Hence, he left.”
• “That’s why he left.”
• “He left because he was tired.”

How “Hence” Should Be Used in Correct English

Hence comes from Middle English, derived from Old English heonan (“away from here”) and siððan (“since then”). It’s an adverb of result or consequence.

Correct Uses:

• “The roads were icy; hence, the accident.”
• “They were underprepared, hence their failure.”
• “He was late. Hence, the confusion.”

Notice that “hence” already means “as a result” – it doesn’t need “why” to explain itself.

Incorrect Usage:

• ❌ “Hence why the delay happened.”
• ❌ “They forgot the deadline, hence why the chaos.”

Rule of Thumb:

Use hence when you can logically replace it with “therefore” or “thus.”

Examples of Correct and Incorrect Usage

To truly grasp how to use “hence” correctly, compare real sentence constructions:

Sentence	Correct?	Why
“He didn’t study, hence why he failed.”	❌ Incorrect	Redundant
“He didn’t study; hence, he failed.”	✅ Correct	Clear cause and effect
“We ran out of time, hence the rush.”	✅ Correct	Concise and formal
“Hence why I left early.”	❌ Incorrect	Unnecessary use of “why”
“I left early; hence, I missed the speech.”	✅ Correct	Proper use of adverb

Using “hence” cleanly adds polish to your writing. Avoid the temptation to stuff it with extra words.

What to Say Instead of “Hence Why”

If “hence why” is off the table, what should you use? Let’s match tone with intent.

Replacement	Best Use Case	Example
Hence	Formal writing	“He skipped class; hence, he failed.”
That’s why	Conversational tone	“He didn’t show up – that’s why I left.”
Because	General explanation	“I left because I was bored.”
Therefore	Academic writing	“The sample was contaminated; therefore, the results are invalid.”
Thus	Scientific/legal writing	“Thus, the hypothesis was disproven.”

Quick Tip:

If you’re writing for a formal audience (e.g., academia, business, government), opt for “hence,” “thus,” or “therefore.” In casual writing or dialogue, “that’s why” works fine.

“Hence” vs. “That’s Why”: What’s the Difference?

While both indicate cause and effect, their formality, tone, and structure differ.

Feature	Hence	That’s Why
Tone	Formal, academic	Casual, conversational
Part of Speech	Adverb	Complete clause
Example	“He lied; hence, the distrust.”	“He lied. That’s why no one trusts him.”
Common Use	Reports, essays, technical writing	Dialogue, personal writing

Think of “hence” as sharp and professional.
Think of “that’s why” as warm and human.

The Linguistic History of “Hence Why”

Believe it or not, “hence why” isn’t brand new. It’s been used in spoken English for decades – particularly in British and Australian English.

Historical Appearances:

• Early 1900s newspapers used “hence why” in columns and opinion pieces.
• British authors like H.G. Wells used phrases that combined formal and colloquial elements.

But even then, grammarians pushed back, labeling such combinations as unnecessary or imprecise.

Modern grammar stylists (like in The Chicago Manual of Style or Oxford Modern English Usage) still advise against it.

How Language Change Affects What’s Considered “Correct”

Language constantly evolves. What’s “wrong” today might be accepted tomorrow – just look at “literally” being used figuratively.

Still, when precision matters – in legal writing, academic work, or professional emails – using phrases like “hence why” can undermine your credibility.

Descriptive vs Prescriptive Grammar:

• Descriptive grammar observes how people actually speak.
• Prescriptive grammar sets rules on how people should speak.

“Hence why” exists in descriptive grammar, but prescriptive guides warn against using it.

Other Redundant Phrases Like “Hence Why”

Once you spot one redundancy, you’ll start seeing others everywhere. Let’s call them out:

Redundant Phrase	Better Alternative
“Return back”	“Return”
“Revert back”	“Revert”
“Close proximity”	“Proximity”
“Past history”	“History”
“End result”	“Result”

These phrases waste words and weaken writing. Trim the fat and say what you mean.

Common Grammar Errors That Reduce Clarity

Here are other grammar hiccups to watch out for:

Cause-Effect Confusion

• ❌ “Because why would he lie?” → Confusing structure
• ✅ “Why would he lie?” OR “Because he wanted to hide the truth.”

Double Negatives

• ❌ “I don’t need no help.”
• ✅ “I don’t need any help.”

Misplaced Modifiers

• ❌ “Running down the street, the trees flew by.” (Did the trees run?)
• ✅ “As I ran down the street, trees flew by.”

Fixing these kinds of mistakes sharpens your communication instantly.

Should You Use “Therefore” or “Thus” Instead?

Yes, “therefore” and “thus” are excellent tools in formal and academic writing. They do the heavy lifting of showing results, conclusions, or logical outcomes.

Connector	Register	Example
Therefore	Formal	“He missed the deadline; therefore, he failed the course.”
Thus	Very formal, often legal or technical	“Thus, the contract was voided.”
Hence	Formal	“The funds were misallocated; hence the delay.”

Grammar Tip:

Use a semicolon or period before these connectors when they join two complete ideas.

“The study was flawed; therefore, its results are questionable.”

Writing for Precision: Grammar Tips from Editors and Linguists

Want to write like a pro? Use these editor-backed tips:

• Trim redundancies: Avoid “hence why,” “past history,” “end result.”
• Read aloud: If it sounds clunky, it probably is.
• Be audience-aware: Write simpler for general readers, more formally for experts.
• Use cause-effect linkers wisely: Choose one – don’t stack them.
• Clarity trumps complexity: The smartest writers are often the clearest.

✍️ “Good writing is clear thinking made visible.” – William Zinsser

Final Thoughts

The phrase “hence why” may sound natural in everyday conversation, but from a grammatical standpoint, it’s redundant. “Hence” already means “for this reason” or “therefore” – so pairing it with “why,” which also signals a reason, is like saying “because why.” It’s a tautology that clutters clear communication.

That said, it has become increasingly common in speech and even informal writing. Still, for formal, academic, or professional contexts, it’s best to choose clearer, more grammatically precise alternatives. Phrases like “hence the reason,” “which is why,” or simply “therefore” do a better job conveying your point without redundancy.

FAQs

Is “hence why” grammatically correct?

No, it’s not. “Hence” already implies a reason or result. Adding “why” repeats that meaning, making the phrase redundant. While common in casual speech, it’s best avoided in formal writing or professional contexts.

Why do people say “hence why” so often?

Because it feels natural in speech. It combines the familiarity of “why” with the formality of “hence.” However, it’s grammatically unnecessary. It’s a blend that has caught on colloquially, but it lacks linguistic precision.

What can I say instead of “hence why”?

Try these alternatives: “which is why,” “thus,” “therefore,” or “hence the reason.” These phrases maintain clarity and formality without being redundant. Pick the one that fits the tone and flow of your sentence best.

Is “hence why” acceptable in academic writing?

Not really. Academic writing values clarity and precision. Since “hence why” is redundant, it can weaken your writing. Use more precise phrases like “therefore” or “which is why” to maintain credibility and professionalism.

Can I use “hence why” in casual writing?

Yes, in casual or conversational writing, “hence why” is widely understood and often accepted. But if you’re aiming for polished or formal content, it’s better to choose grammatically accurate alternatives for clarity.