in certain days

USAGE SUMMARY

The phrase "in certain days" is not correct in standard written English.
The correct expression would be "on certain days," which is used to refer to specific days of the week or month. Example: "The store is open late on certain days, so check the schedule before you visit."

⚠ May contain grammatical issues

Wiki

News & Media

Science

Human-verified examples from authoritative sources

Exact Expressions

3 human-written examples

Joining the Raëlian Church through transmission of the cellular plan happens only in certain days of the year.

Wikipedia

Do you know which room they will be in certain days or times and not go in there?

WikiHow

Check with human resources to see if the company has built in certain days that don't fall under the umbrella of sick or vacation time.

WikiHow

Human-verified similar examples from authoritative sources

Similar Expressions

57 human-written examples

To the extent Ms. Parker keeps a hand in certain day-to-day tasks, she said, "It's because I'm a control freak and I like those things".

The New York Times

But also if you have a job you may need to load in classes on certain days or late in the day or on weekends.

HuffPost

Restaurants sometimes want to bring in customers on certain days when they do not normally receive a lot of customers, such as Mondays and Tuesdays.

WikiHow

Admission has been free from the start – though in its early years the public was only allowed in on certain days and nursemaids with babies and young children were banned.

The Guardian

The first person may tell you the person you seek "prefers to be emailed," or "is only in on certain days".

Huffington Post

During our analysis of the daily variations in cardiac function in the present 6-month (summer and fall) subchronic CAPs inhalation study, we noted the presence of a number of dramatic changes in cardiac function on certain days in the fall months.

Environmental Health Perspectives

In the last year, Faith Hope Consolo, chairwoman of the retail leasing, marketing and sales division of Prudential Douglas Elliman, has overseen six leases in which the client would not sign in certain locations, on certain days and even in certain hours.

The New York Times

Of course I am not blind to the iniquities of my church; but in Rome, on certain days, they seem to pale, to exert so minimal a pull on the imagination as to be almost irrelevant.

The New York Times - Magazine

Expert writing Tips

Best practice

Replace "in certain days" with the correct preposition "on", using "on certain days" to refer to specific days when an event or activity occurs.

Common error

Avoid using "in" when referring to specific days. "In" is generally used for periods like "in the morning" or "in July". Use "on" to specify particular days, like "on Monday" or "on certain days".

Linguistic Context

The phrase "in certain days" functions as an adverbial phrase, attempting to specify when an action or event takes place. However, as indicated by Ludwig AI, the correct preposition to use with specific days is "on", making the phrase grammatically incorrect.

Expression frequency: Rare

Frequent in

Wiki

33%

News & Media

33%

Science

33%

Less common in

Encyclopedias

0%

Reference

0%

Formal & Business

0%

Ludwig's WRAP-UP

In summary, the phrase "in certain days" is grammatically incorrect. According to Ludwig AI, the correct preposition is "on", making "on certain days" the appropriate alternative. While examples of the incorrect phrase exist, they are rare and spread across informal sources and do not represent standard English usage. To ensure clarity and grammatical correctness, replace "in certain days" with "on certain days" in your writing.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

on specific days

Replaces "certain" with "specific", emphasizing particular days.

on particular days

Uses "particular" instead of "certain", highlighting select days.

during certain days

Emphasizes the period or duration of those specific days.

on some days

A more general term indicating that something happens on a few days.

on designated days

Highlights that the days are officially chosen or assigned.

on selected days

Indicates that the days have been carefully picked.

during specified days

Similar to 'designated' but indicates that something occurs during set or required times.

on fixed days

Stresses the regularity and unchangeable nature of these days.

at certain daytimes

Refers to the time of the day only, but not to specific days.

within certain days

Indicates that something should happen before a set deadline.

FAQs

What is the correct way to say "in certain days"?

The correct way to phrase this is "on certain days". The preposition "on" is used to refer to specific days of the week or month.

What can I use instead of "in certain days"?

You can use "on specific days", "on particular days", or "during certain days" as alternatives.

Is it grammatically correct to use "in" when referring to days?

No, it is not grammatically correct. Use "on" to refer to specific days. "In" is typically used for months or years, while "on" is used for specific dates or days.

How do I use "on certain days" in a sentence?

Example: "The library is closed "on certain days" for maintenance."