When and How to Use “in” and “on” in Some Fixed Expressions

By Farooq A. Kperogi, Ph.D. Twitter: @farooqkperogi Several readers have asked me to give them some guidance on when it is proper to...

By Farooq A. Kperogi, Ph.D.

Twitter: @farooqkperogi

Several readers have asked me to give them some guidance on when it is proper to use the locational prepositions “in” and “on” in certain fixed expressions. They asked to know the difference between “in bed” and “on the bed,” between “in the train” and “on the train,” between “in the street” and “on the street,” between “in the bus” and “on the bus,” between "on the airplane" and "in the airplane," etc. This week’s column answers these questions.

1. “In bed” versus “on the bed.”  “In bed” is the conventional expression in Standard English to indicate that one is sleeping or is about to sleep, as in, “By 8:30 p.m. all the children should be in bed.”  The expression can also mean sexual activity, as in, “He is good in bed.”  “On the bed,” on the other hand, merely indicates one’s location in relation to a bed. For instance, someone can sit “on the bed” or “lie on the bed,” which merely indicates the person’s position on the bed. It doesn’t convey the sense that the person is sleeping or is about to sleep.

 In sum, use “in bed” for sleeping and sexual activity and “on the bed” to convey the sense of being on top of the blankets of a bed— with no intention to sleep.

2. “In the street” versus “on the street.” The difference between “in the street” and “on the street” isn’t as straightforward as that between “in bed” and “on the bed.” Many native speakers interchange the expressions. But here is what the sensitive user of the language needs to know.

“In the street” is an older, more established expression than “on the street” when reference is to the roads and public places of a village, town, or city in the abstract sense, as in, “I like to go for a walk in the street every weekend.” In this example, “street” isn’t specific to any identifiable public road. “On the street” tends to be appropriate for occasions when the specific location of a street is important, as in, “we live on the same street.” Here, the street is identifiable and known.

The truth, though, is that in modern usage, both expressions can be, and often are, used in place of the other. My own preference is “in the street.”  

How about the idiom “man in the street” to represent the hypothetical everyday person who is a non-expert? Should it be “man on the street”? Well, both expressions are now usually interchanged in popular usage, and there is no reason to chafe at this. In fact, many prestigious dictionaries acknowledge the interchangeability of the expressions. It helps to know, though, that “man in the street” is the older form of the expression, and current usage still prefers it to “man on the street.”  A search on Google brought nearly 1.5 billion hits for “man in the street” but only 547 million hits for “man on the street.” 

However, evidence from the British National Corpus and the Corpus of Contemporary American English shows strong regional and dialectal variations in the use of these expressions.  “Man in the street” enjoys more popularity and acceptance than “man on the street” in British English. I found only 5 hits for “man on the street” in the British National Corpus. Of the five hits, only one usage is idiomatic. The only other idiomatic usage puts it in quotation marks and makes it clear that it’s an American usage (“I wish a prominent member of the American print media would present an open unbiased, informative ‘Man on the street’ issue, such as you did.”) The three other uses refer to a man on a specific street.

The Corpus of Contemporary American English shows a preference for “man on the street” but not by the wide margin we saw between “man in the street” and “man on the street” in the British National Corpus. It seems safe to say that “man on the street” first appeared in American English, and hasn’t quite become popular yet in British English.

The Online Etymology Dictionary says the first recorded use of “man in the street” to mean the ordinary person dates back to 1831. “Man on the street,” on the hand, the Merriam-Webster Dictionary says, dates back only to 1926.

It is also important to note that “on the streets” (note the plural) means being homeless (as in, “if you don’t pay your rent you will be on the streets”) or working as a prostitute (as in, “The government should devise policies to protect the girls on the streets in our cities”).

“In the street” (note that there is no plural) can also mean “without a job, unemployed,” especially in American English, as in, “After she lost her job at the ministry she was on the street for three years.” The American Heritage Idioms Dictionary says this idiom is attested from the “first half of 1900s.”

3. “On the train” versus “in the train.” When you’re traveling by means of a train, you say you’re “on the train.” That’s the fixed, conventional expression to use in all native varieties of English. Being “in the train” indicates your position in relation to the train (that is, that you’re inside it), not the fact of your traveling by it. 

Note that this is different from the idiomatic expression “in the train of,” which is synonymous with “in the wake of,” as in, “many people were rendered homeless in the train of the massive flood.” Also note that “in train” is another fixed phrase that means “well-organized” or “in progress,” as in, “The report of the recently concluded national conference is in train.”

In short, in transportational contexts “on the train” is the preferred expression. 

4. “On the bus” versus “in the bus.” The usage rules here are similar to the preceding one. It should be “on the bus” when you use the expression in a transportational context. “In the bus” is never appropriate when used in relation to transport. It may be used to show position such as being inside the bus.

You also you get “on an airplane,” not “in an airplane.” The same rule applies to bicycle. You ride “on a bicycle.”

5. “In the car” versus “on the car.” Here the rule is reversed. You are “in a car” if you’re traveling by car. When you’re “on a car” it means you’re on top of it. You also get “in a taxi,” not “on a taxi.”

A good way to help the reader remember when it’s appropriate to use “in” or “on” in relation to a means of transportation is to note the prepositions we use to get out of the means of transportation. You get “out” of a car. So you get “in” it. You get “off” a train. So you get “on” it. We say “in and out” but “on and off.”

Some Thoughts on Prepositions                        

If this column isn’t very helpful in its differentiation of “on” and “in,” it’s because English prepositions are notoriously tricky and can’t seem arbitrary. You can’t master their usage by holding on to a universal syntactic logic. You just need to learn their usage through reading good books and articles or by listening to the speech patterns of native speakers. 

In some cases, prepositional usage can be fluid, permissive, and inflected by dialectal choices (such as is the case with “in the street” and “on the street”), but in other contexts their usage is fixed in meaning and context (such as in the use of “on” or “in” in relation to transportational activities).