every fifth hour

USAGE SUMMARY

The phrase "every fifth hour" is correct and usable in written English.
You can use it to indicate a recurring event or action that takes place once every five hours. Example: "The train departs every fifth hour, so make sure to check the schedule for the next available time."

✓ Grammatically correct

Science

News & Media

Human-verified examples from authoritative sources

Exact Expressions

1 human-written examples

The fed-batch experiments were performed with an initial WIS content of 6%, and slurry was added in equal pulses every fifth hour up to 20 h of fermentation.

Biotechnology for Biofuels

Human-verified similar examples from authoritative sources

Similar Expressions

59 human-written examples

CSF and blood samples were obtained every second hour during a 16-hours study period and were analyzed for bacterial concentrations by quantitative cultures (lower detection level: 50 CFU/ml) and WBC on an automatic cell counter (Swelab, Åstad, Sweden).

BMC Infectious Diseases

Every third hour, you squeeze a Monopoly-race-car-sized amount onto the tips of your fingers (right hand), and then dab your ends with it.

The New Yorker

Consecutive sampling of aldehydes every eighth hour as well as total aldehyde sampling was performed during the first 5 days after application of the paints.

Industrial Crops and Products

N = 34 professional driver students drove in a high-fidelity driving simulator at 80 km/h for 55 min every third hour during 36 h of sustained wakefulness.

Accident Analysis & Prevention

Eight blood samples were drawn each day (every third hour) on 8 days of the protocol and analyzed with respect to IL-6 and TNF-α.

Brain, Behavior, and Immunity

Urinary output was measured, and urine samples from both kidneys were collected at baseline, after 90 min and thereafter every second hour.

Intensive Care Medicine Experimental

The occurrence of aggressive behaviour, play behaviour and synchronous resting was recorded throughout the day (i.e. every third hour for 15 min during 24 h) on day 1, day 5, day 19 and day 33 after mixing.

Applied Animal Behaviour Science

Imagine a job that only paid you for every second hour you worked and threatened to have you kicked out of the country if you complained.

Vice

After cell cycle arrest by serum-starvation, BrdU was incorporated for 1 h in serum-rich medium after which cells were harvested every second hour.

Plosone

The perfusate was collected every third hour.

Critical Care

Expert writing Tips

Best practice

When describing a schedule or experimental protocol, use "every fifth hour" to clearly indicate the frequency of an action. For improved readability, consider rewording the sentence or using alternative, simpler phrases like "every five hours".

Common error

Avoid mistaking "fifth" (an ordinal number indicating position in a sequence) for "five" (a cardinal number indicating quantity). Using "every five hour" is grammatically incorrect; the correct form is "every fifth hour" or, more commonly, "every five hours".

Linguistic Context

The phrase "every fifth hour" functions as an adverbial phrase modifying a verb, specifying when or how often an action occurs. Ludwig AI indicates that it's usable, although less common than other alternatives. Examples show its use in scientific contexts.

Expression frequency: Rare

Frequent in

Science

60%

News & Media

40%

Formal & Business

0%

Less common in

Encyclopedias

0%

Wiki

0%

Reference

0%

Ludwig's WRAP-UP

The phrase "every fifth hour" serves as an adverbial phrase to specify the frequency of an action, as shown in the examples from Ludwig AI. While grammatically correct, Ludwig indicates that it is less common than simpler alternatives like "every five hours". Its use is primarily found in scientific and technical contexts when describing experimental protocols or structured schedules. For general writing, prioritizing clarity may suggest using the more common alternative.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

every five hours

More common and direct way of expressing the same interval.

once every five hours

Adds emphasis on the singular occurrence within the interval.

at five-hour intervals

Focuses on the intervals themselves rather than the specific occurrence.

every 300 minutes

Expresses the interval in minutes instead of hours.

five hours apart

Highlights the separation in time between events.

every fifth hourly cycle

Adds a cyclic context to the interval.

at five hour periodicity

More formal and scientific way to define interval.

quinquihourly

Uses a less common, single-word adjective to indicate frequency.

every rotation of five hours

Describes the interval from rotational perspective.

on a five-hour schedule

Implies a planned or arranged timing pattern.

FAQs

How can I use "every fifth hour" in a sentence?

You can use "every fifth hour" to describe an action or event that occurs once every five hours. For example, "The machine requires maintenance every fifth hour to prevent overheating".

What is a more common alternative to "every fifth hour"?

A more common and simpler alternative is "every five hours". This phrasing is generally preferred for its clarity and conciseness.

Is it grammatically correct to say "every five hour" instead of "every fifth hour"?

No, "every five hour" is grammatically incorrect. The correct phrasing is either "every fifth hour" (less common) or "every five hours" (more common).

What is the difference between "every fifth hour" and "every five hours"?

While both phrases indicate a recurrence at five-hour intervals, "every fifth hour" emphasizes the sequential position in a series, whereas "every five hours" simply states the duration between occurrences. In most contexts, "every five hours" is preferred for its simplicity.