A prepositional phrase is a group of words that consists of a preposition, its object, and any modifiers. Every prepositional phrase is a group of words that lacks either a verb or a subject, and that functions as a unified part of speech. These words can be complements of verbs.

prepositional phrase = preposition + optional modifier(s) + noun, pronoun, gerund, or short clause.

Here is the list of 136 Prepositional Phrases Examples formed with IN, AT, ON, BY – Learn them by heart to enhance your vocabulary. 

IN ON AT BY
• in time • on watch • at high speed • by law
• in demand • on schedule • at risk • by nature
• in of focus • on the record • at one’s side • by far
• in an uproar • on the road • at a fraction of • by design
• in answer to • on oath • at the outset • by chance
• in anticipation of • on pain of • at the end • by the name of
• in arrears • on the air • at sight • by luck
• in danger • on balance • at the double • by accident
• in debt • on a diet • at one time • by air
• in decline • on a journey • at a discount • by sea
• in defense of • on a trip • at a distance • by land
• in detail • on a large scale • at a glance • by all accounts
• in disgrace • on a small scale • at a guess • by all means
• in disguise • on a pension • at a loose and • by any standard
• in fact • on a regular basis • at a loss • by appointment
• in fairness to • on a spree • at a low ebb • by birth
• in favor of • on account of • at a price • by check
• in fear of • on an expedition • at a rate of • by coincidence
• in flames • on an island • at a speed of • by courtesy of
• in flower • on approval • at a standstill • by definition
• in full • on average • at all costs • by degrees
• in future • on bail • at all events • by design
• in gear • on behalf of • at issue • by dint of
• in general • on board • at large • by far
• in good condition • on business • at least • by force
• in good faith • on order • at length • by hand
• in hand • on remand • at liberty • by heart
• in harmony (with) • on show • at most • by law
• in haste • on strike . at night • by marriage
• in hiding • on suspicion of • at noon • by means of
• in high spirits • on the agenda • at one’s leisure • by mistake
• in honor of • on the brink of • at one’s request • by no means
• in horror • on the dot • at peace • by request
• in ink • on the edge of • at war • by sight

Source by abdelwahebham