that is when

USAGE SUMMARY

"that is when" is a correct and usable phrase in written English.
You can typically use it when introducing a situation that occurred after a specific point in time. For example: "He graduated from college in 2019 - that is when he decided to pursue a career in finance."

✓ Grammatically correct

News & Media

Academia

Science

Human-verified examples from authoritative sources

Exact Expressions

60 human-written examples

That is when it sucks.

The New Yorker

That is, when it's true.

The New York Times

That is when the love affair began.

The New York Times

That is when Mohammed went after him.

The New York Times - Sports

And that is when Brokaw quit.

The New York Times - Magazine

"That is when we get very offended".

The New York Times

That is when Fela considered leaving Nigeria.

The New Yorker

That is when things turned eerie.

The New York Times - Sports

Presumably, that is when he was killed.

The New Yorker

That is when major developments are completed.

Independent

That is when the writing gets done.

The New Yorker

Expert writing Tips

Best practice

Use "that is when" to clearly indicate a specific point in time when a subsequent event occurred. This helps to create a smooth narrative flow.

Common error

Avoid using "that is when" to introduce explanations or reasons that are not directly related to a specific moment in time. Instead, opt for phrases like "that is why" or "that is because" for causal relationships.

Linguistic Context

The phrase "that is when" functions as an adverbial phrase introducing a time clause, specifying the moment an event occurs. As noted by Ludwig AI, it effectively links a situation to a precise point in time. Examples across various sources consistently demonstrate this temporal function.

Expression frequency: Very common

Frequent in

News & Media

65%

Academia

15%

Science

10%

Less common in

Formal & Business

5%

Encyclopedias

3%

Wiki

2%

Ludwig's WRAP-UP

In summary, "that is when" is a versatile phrase used to indicate the specific time an event happens. As Ludwig AI confirms, it's grammatically sound and widely accepted. It's best used to connect events chronologically, and it maintains a neutral tone suitable for various contexts. While highly prevalent in "News & Media", it sees frequent application in academic and scientific writing as well. Just remember to avoid misusing it to indicate causality; in such cases, "that is why" or "that is because" are more appropriate.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

that's the moment

Replaces "when" with "the moment" for a slightly more emphatic tone.

that's the time

Substitutes "when" with "the time", focusing on the duration or occasion.

it was at that point

Uses a more formal and narrative structure to introduce the event.

at that juncture

Replaces "that is when" with a more sophisticated expression, implying a critical moment.

it happened then

Simplifies the structure while maintaining the temporal reference.

that's when it all started

Adds an element of narrative emphasis, suggesting the beginning of a series of events.

that was the occasion

Focuses on a specific event as the reason for subsequent actions.

then came the moment

Inverts the sentence structure to emphasize the arrival of a particular time.

subsequently

Uses a single adverb to indicate the temporal sequence more concisely.

thereafter

Offers a formal and succinct way to convey the idea of 'after that time'.

FAQs

How can I use "that is when" in a sentence?

"That is when" is used to specify the time at which an event occurred or a situation changed. For example, "He finished his degree in 2020; "that is when" he started his own company".

What phrases are similar to "that is when"?

Alternatives include "at that point", "then", "subsequently", or "thereafter". The choice depends on the context and desired level of formality.

Is it ever incorrect to use "that is when"?

Yes, it's incorrect if used to explain a cause rather than indicate a time. Use "that is why" or "that is because" instead when explaining reasons.

What's the difference between "that is when" and "that is where"?

"That is when" refers to a specific point in time, while "that is where" refers to a specific location. For example, "The accident occurred at 5 PM; that is when" the traffic was heaviest" vs. "He grew up in New York; that is where" he learned to play jazz".