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Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.

Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com
while class is in session
Grammar usage guide and real-world examplesUSAGE SUMMARY
The phrase "while class is in session" is correct and usable in written English.
It can be used to indicate that something is happening during the time that a class is actively taking place. Example: "Please refrain from using your phones while class is in session to maintain a focused learning environment."
✓ Grammatically correct
News & Media
Science
Wiki
Alternative expressions(20)
during plan time
during lecture time
during class period
during nonwork time
during school hours
in the classroom
during instruction
during refreshment time
during school time
during one time
during class
as the class proceeds
during work time
during class hour
while in class
in class
during the lesson
while attending class
during classroom time
during class time
Table of contents
Usage summary
Human-verified examples
Expert writing tips
Linguistic context
Ludwig's wrap-up
Alternative expressions
FAQs
Human-verified examples from authoritative sources
Exact Expressions
1 human-written examples
Peek into DevMountain on any afternoon while class is in session and you'll see about a hundred students eagerly listening, laptops open and a series of neon lines of code popping up against black backdrops as their teacher leads the discussion in one of the many rooms, named after certain ski parks along the Wasatch Front.
News & Media
Human-verified similar examples from authoritative sources
Similar Expressions
59 human-written examples
Three people were killed on Friday, including two people who died during an attack while class was in session at a Wyoming community college, the police said.
News & Media
The reasons included the timing of the quake, while classes were in session, and the age of school buildings.
News & Media
About 1,200 seats are earmarked for Duke's undergraduates, but this season students have filled about 700 a game while classes are in session.
News & Media
When choosing among several colleges, visit the colleges while classes are in session to see how comfortable you feel at each college.
News & Media
With "Election," he wanted to film in a typically drab high school with cinder-block walls, and eventually found one — Papillion-La Vista, just outside Omaha — that he was allowed to use while classes were in session.
News & Media
Reports from the district indicate that an even greater death toll is possible, since the enrollment of the school is 1,300 and the blast occurred while classes were in session.
News & Media
Interviewee E-2 described how this happened "While classes were in session, we'd invite [alumni or esteemed visitors] into our classes, but if classes weren't in session, we would hold a class for other people so they could see what we were doing.
On the other hand, Goodman observed a drop in test scores among schools where students stayed home while classes were in session.
News & Media
Cheerleading coach Sue Sylvester Jane Lynchh) publicly humiliates Will by playing the message he left on her voice mail not Emma's, as he had meant to do—over the school's public address system while classes are in session.
Wiki
It's Saturday afternoon, and modelling class is in session.
News & Media
Expert writing Tips
Best practice
Use "while class is in session" to clearly indicate that an action or event occurs during the active period of a class. This helps to set the context and timing of the action.
Common error
Avoid using "while class is in session" in very casual conversations. Simpler alternatives like "during class" are often more appropriate.
Source & Trust
83%
Authority and reliability
4.5/5
Expert rating
Real-world application tested
Linguistic Context
The phrase "while class is in session" functions as an adverbial phrase, modifying a verb or clause to indicate when an action occurs. Ludwig confirms its correctness and usability.
Frequent in
News & Media
45%
Science
25%
Wiki
10%
Less common in
Formal & Business
10%
Encyclopedias
5%
Reference
5%
Ludwig's WRAP-UP
In summary, the phrase "while class is in session" serves to define the timing of an action, indicating it happens during class time. Grammatically sound and recognized by Ludwig as correct, it is commonly used in a variety of contexts, including news and media, science, and Wiki articles. While the phrase is quite versatile, be mindful of overly formal tone in very casual settings, where alternatives may be better suited. The Ludwig examples showcase various applications, providing clear boundaries and setting conditions related to classroom activities.
More alternative expressions(6)
Phrases that express similar concepts, ordered by semantic similarity:
during class time
Replaces the entire phrase with a more concise expression.
during the lesson
Substitutes 'class' with 'lesson', keeping the same structure.
while the class is ongoing
Rephrases 'in session' to 'is ongoing', offering a slightly different nuance.
while lessons are being taught
More descriptive, specifying the activity occurring in the class.
while the lecture is underway
Focuses on the lecture aspect of a class.
during instructional periods
More formal and academic alternative.
while the course is active
Highlights the active state of a course.
when class is being held
Shifts focus to the act of holding the class.
as the class proceeds
Describes the progression of the class.
when the teaching is in progress
More descriptive and emphasizes the teaching aspect.
FAQs
What does "while class is in session" mean?
The phrase "while class is in session" means during the time when a class is actively being taught or taking place.
What can I say instead of "while class is in session"?
You can use alternatives like "during class time", "during the lesson", or "while the class is ongoing" depending on the context.
How do I use "while class is in session" in a sentence?
You can use it to describe actions or events that occur during class time, such as "Please do not use your phone while class is in session".
Is it more formal to say "while class is in session" or "during class"?
"While class is in session" is generally more formal than "during class". Use "while class is in session" in formal settings or when emphasizing the specific timing of an event.
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Table of contents
Usage summary
Human-verified examples
Expert writing tips
Linguistic context
Ludwig's wrap-up
Alternative expressions
FAQs
Source & Trust
83%
Authority and reliability
4.5/5
Expert rating
Real-world application tested