at two hour intervals

USAGE SUMMARY

The phrase "at two hour intervals" is not correct in standard written English; it should be "at two-hour intervals." You can use it when describing a schedule or frequency of events occurring every two hours.
Example: "The medication should be taken at two-hour intervals to ensure its effectiveness."

⚠ May contain grammatical issues

Science

Wiki

News & Media

Human-verified examples from authoritative sources

Exact Expressions

5 human-written examples

These were followed at two hour intervals by Foresight and Prudence in the evening.

Wikipedia

The fix frequency was set at two hour intervals.

Plosone

Blood samples for the measurement of ScvO2 and haemoglobin were taken after induction of anaesthesia and thereafter at two hour intervals up to 12 hours postoperatively.

Critical Care

In 60 patients with intra-abdominal surgery lasting more than 90 minutes, the presence of at least two of Shoemaker's criteria, and ASA (American Society of Anesthesiologists) class greater than 2, ScvO2 was determined preoperatively and at two hour intervals during the operation until 12 hours postoperatively.

Critical Care

Volumetric and hemodynamic variables, ventilation mechanics and blood gases were determined at baseline (BL), after lateral thoracotomy (TT), after pneumonectomy (PE; time 0), and subsequently at 1 hour intervals until the end of the experiment (in tables, data are presented only at two hour intervals after PE).

BMC Anesthesiology

Human-verified similar examples from authoritative sources

Similar Expressions

55 human-written examples

A405 readings were taken on a plate reader at four hour intervals.

Plosone

Briefly, 10 20 flies were sacrificed and prepared for histology at three hour intervals throughout a 24-hour period.

Plosone

Male Drosophila were collected for ethoxycoumarin-O-deethylase (ECOD), esterase, glutathione-S-transferase (GST), and, and uridine 5'-diphosphoglucosyltransferase (UGT) enzyme activity assays, or subjected to dose-response tests at four hour intervals throughout the day in both light/dark and constant light conditions.

Plosone

Cardiorespiratory parameters were systematically recorded at six hour intervals.

Critical Care

Alternatively, cells were counted manually at twelve hour intervals using a hemacytometer.

Biochimica et Biophysica Acta - Clinical

Four doses of dexamethasone (0.25 mg/kg) given at eight hour intervals could prevent stridor in preterm infants [ 28].

Critical Care

Expert writing Tips

Best practice

Use the grammatically correct form "at two-hour intervals" when describing events that occur every two hours. This clarifies that "two-hour" is a single descriptive unit.

Common error

Avoid writing "at two hour intervals". The hyphen in "two-hour" is essential because it groups "two" and "hour" to act as a single adjective modifying "intervals". Without it, the phrase becomes grammatically incorrect.

Linguistic Context

The phrase "at two hour intervals" functions adverbially, specifying when or how often an action occurs. However, it's considered grammatically incorrect. As Ludwig AI indicates, a hyphen is needed to join "two" and "hour" into a compound adjective.

Expression frequency: Uncommon

Frequent in

Science

50%

News & Media

17%

Wiki

17%

Less common in

Formal & Business

0%

Social Media

0%

Encyclopedias

0%

Ludwig's WRAP-UP

In summary, while the phrase "at two hour intervals" is understandable, it is grammatically incorrect. The correct form is "at two-hour intervals", where "two-hour" acts as a compound adjective. As noted by Ludwig AI, a simpler alternative is "every two hours". The phrase is primarily found in scientific and medical contexts, but its usage is relatively uncommon and should be avoided in informal writing. Always use the hyphenated form for grammatical correctness and clarity.

More alternative expressions

Phrases that express similar concepts, ordered by semantic similarity:

every two hours

Replaces "at two hour intervals" with a more common and grammatically correct expression.

at two-hour intervals

Corrects the grammatical error by adding a hyphen, making it an adjective modifying 'intervals'.

bi-hourly

Uses a single word to convey the meaning of occurring every two hours.

every other hour

Emphasizes the separation between the occurrences.

twice every day

Focuses on the daily frequency of an event happening twice.

occurring every second hour

A more verbose but clear way of saying 'every two hours'.

spaced two hours apart

Highlights the temporal distance between events.

with a two-hour separation

Similar to 'spaced two hours apart', emphasizing the gap.

at intervals of two hours

More formal phrasing emphasizing the regularity.

every 120 minutes

Expresses the interval in minutes for added precision.

FAQs

How can I correctly use "at two-hour intervals" in a sentence?

Use "at two-hour intervals" to indicate that something occurs every two hours. For example: "The medication should be administered "at two-hour intervals"."

What's a more common way to say "at two hour intervals"?

A more common and grammatically correct alternative is "every two hours". For example: "The checks are performed "every two hours"."

Is it better to say "at two-hour intervals" or "at two hourly intervals"?

"At two-hour intervals" is generally preferred because it is concise and clear. "At two hourly intervals" is also correct, but slightly less common.

What other phrases indicate recurring actions with a set time frame?

Other phrases include "bi-hourly", "every other hour", or "spaced two hours apart", depending on the specific nuance you want to convey.