period when

USAGE SUMMARY

The phrase "period when" is not correct in written English.
To use "when" correctly in a sentence, it must be followed by a clause. For example, "The period when I was in high school was very memorable."

⚠ May contain grammatical issues

News & Media

Science

Human-verified examples from authoritative sources

Exact Expressions

60 human-written examples

Another Period When does it premiere?

The Guardian - TV & Radio

It's a period when anything can happen".

The New York Times

"It's for that critical period when you're starving".

The New York Times

"It was a period when people weren't making musicals".

The New York Times

It evokes a period when people were trying to escape".

The New York Times

They date back to the period when N.Y.

The New Yorker

"That's the period when Meissen was it," Mr. Arnhold said.

The New York Times - Arts

They had a period when they couldn't win a lineout.

The Guardian - Sport

Could this be the period when Sweden almost score?

The Guardian - Sport

There was a period when everything contained cinnamon.

The New York Times - Travel

There was a brief period when it was even $95.

The New York Times

Expert writing Tips

Best practice

Prefer using more grammatically correct alternatives such as "time when" or "period in which" to improve clarity and professionalism in your writing.

Common error

Avoid using "period when" as it can be seen as redundant. The word "period" already implies a span of time, so adding "when" can make the phrase sound awkward. Consider using "period in which" or simply "time when" instead.

Linguistic Context

The phrase "period when" functions as a relative clause introducing additional information about a specific timeframe. Ludwig AI indicates that it's often used to specify when something occurred or was the case, though it's considered grammatically incorrect.

Expression frequency: Very common

Frequent in

News & Media

69%

Science

14%

Formal & Business

7%

Less common in

Academia

0%

Encyclopedias

0%

Wiki

0%

Ludwig's WRAP-UP

In summary, while the phrase "period when" is frequently used, as shown by Ludwig's examples, it's considered grammatically incorrect. Ludwig AI notes its common appearance in news and media, suggesting a more relaxed standard. For formal writing, alternatives such as "time when", "period in which", or "stage at which" are more appropriate. The choice depends on the specific context and desired level of formality. Be mindful of redundancy, and aim for clarity and grammatical accuracy in your writing.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

time when

Replaces "period" with "time", offering a more grammatically sound alternative.

moment when

Substitutes "period" with "moment", suitable for shorter durations or specific instances.

the era in which

Uses a more formal construction, specifying a broader historical or cultural context.

the stage at which

Employs "stage" to denote a phase or point in a process.

phase in which

Indicates a distinct part of a process or cycle.

duration when

Highlights the length of time something occurs.

interval during which

Provides a formal alternative to describe a span of time.

the age that

Refers to a specific era or long duration.

year that

References a specific year or period of a year.

season when

Specifies a particular season or time of year.

FAQs

How can I correctly use "period" to refer to a specific time?

You can use constructions like "the period in which" or "the time when" to refer to a specific duration. For instance, "the period in which the Roman Empire expanded" or "the time when dinosaurs roamed the Earth" are both grammatically sound.

What are some alternatives to "period when" that sound more professional?

Consider using alternatives like "time when", "phase in which", or "era in which" depending on the context. These alternatives provide clarity and grammatical correctness.

Is "period when" grammatically correct in English?

While commonly used, "period when" is often considered grammatically awkward. It's generally better to use phrases like "period in which" or simply "time when" for improved clarity and grammatical accuracy.

What's the difference between "period when" and "period in which"?

"Period in which" is generally considered more grammatically correct than "period when". While both aim to describe a duration, "period in which" provides a smoother and more standard construction. For example, "the period in which the Renaissance flourished" is preferable to "the period when the Renaissance flourished".