Commas
Fix the sentence:
The study was thorough precise and well-researched.
The study was thorough, precise, and well-researched.
Fix the sentence:
Its time to begin the test.
It’s time to begin the test.
Choose the correct punctuation:
The textbook was expensive it cost over $200 but it was required.
The textbook was expensive—it cost over $200—but it was required.
(Em dashes used to insert a strong interruption.)
Fix the punctuation:
She has one main goal to graduate with honors.
She has one main goal: to graduate with honors.
What is wrong with this sentence?
The internship, which was unpaid provided valuable experience for my future career.
The internship, which was unpaid, provided valuable experience for my future career.
(Missing comma around nonrestrictive clause.)
Identify the error:
The article which was peer-reviewed was published in a leading journal.
The article, which was peer-reviewed, was published in a leading journal.
Identify the error:
The libraries hours are posted on the door.
The library’s hours are posted on the door.
Fix the punctuation:
The final exam (which covers the entire semester) will be held next Friday.
✅ Correct as written.
(Parentheses correctly enclose extra, non-essential information.)
Choose the correct punctuation:
I was tired I stayed up to finish the paper.
I was tired; I stayed up to finish the paper.
What’s wrong with this sentence?
Its important to proofread youre final draft carefully.
It’s important to proofread your final draft carefully.
(“Its” should be “It’s,” and “youre” should be “your.”)
Add commas for clarity:
Before presenting the speaker checked her notes took a deep breath and smiled.
Before presenting, the speaker checked her notes, took a deep breath, and smiled.
Correct the plural possessive:
The students schedules were emailed last week.
The students’ schedules were emailed last week.
Use parentheses or em dashes in this sentence:
The speaker who by the way has three PhDs, captivated the audience.
Em dashes are correct. Use em dashes to emphasize or interrupt in a more dynamic way than parentheses.
(Parentheses would underplay the detail; em dashes add tone.)
The speaker who—by the way—has three PhDs, captivated the audience.
Insert punctuation:
There are three reasons for his success discipline passion and consistency.
There are three reasons for his success: discipline, passion, and consistency.
Correct the sentence:
Neither the professor nor the students was aware that the projector didn’t work.
Neither the professor nor the students were aware that the projector didn’t work.
(Correct subject-verb agreement: plural subject “students” closest to the verb.)
Punctuate this compound-complex sentence:
Although the experiment failed the researcher documented her findings and she proposed a revised method.
Although the experiment failed, the researcher documented her findings, and she proposed a revised method.
Choose the correct form:
Each candidates platform was reviewed carefully.
Each candidate’s platform was reviewed carefully.
Fix the punctuation:
The results of the experiment (which were delayed for several weeks—showed no significant change.
The results of the experiment—which were delayed for several weeks—showed no significant change.
(Mismatched punctuation—should use em dashes, not a parenthesis and dash mixed.)
Fix the sentence using a semicolon and conjunctive adverb:
She missed the seminar however she read the summary.
She missed the seminar; however, she read the summary.
Many students who take night classes, have full-time jobs during the day.
Many students who take night classes have full-time jobs during the day.
(No comma is needed before "have.")
Add commas where needed:
After reviewing the article and discussing the methodology with her advisor who had recently published a similar study the student revised her research proposal and submitted it to the board for approval.
After reviewing the article and discussing the methodology with her advisor, who had recently published a similar study, the student revised her research proposal and submitted it to the board for approval.
Fix both errors:
Its easy to forget other peoples opinions matter.
It’s easy to forget other people’s opinions matter.
Fix the punctuation:
Many students—particularly those in STEM (struggled with the writing requirement).
Many students—particularly those in STEM—struggled with the writing requirement.
(parentheses used incorrectly—use em dashes to set off the interrupting clause.)
Correct the sentence:
The committee considered three proposals one for sustainability one for equity and one for innovation; and they selected the most comprehensive one.
The committee considered three proposals: one for sustainability, one for equity, and one for innovation; they selected the most comprehensive one.
What’s wrong?
When writing an argumentative essay students must clearly state their thesis support it with evidence and anticipate counterarguments.
When writing an argumentative essay, students must clearly state their thesis, support it with evidence, and anticipate counterarguments.
(Added comma after intro phrase and to separate list items.)