Fixed Prepositional Phrases
By chance, on time, in the end — common phrases to learn as units.
Show rules
What are fixed prepositional phrases?
Some common expressions always use the same preposition. They don't follow a logical rule — you simply learn each one as a whole unit.
Phrases with "by"
by chance, by accident, by mistake, by heart, by hand, by far
✅ I met an old friend by chance.
✅ She learned the poem by heart.
Phrases with "on"
on time, on purpose, on foot, on holiday, on sale, on average
✅ The train left exactly on time.
✅ They went to work on foot.
Phrases with "in"
in the end, in time, in fact, in a hurry, in advance, in general
✅ In the end, we decided to stay home.
✅ Book the tickets in advance.
Phrases with "out of"
out of order, out of date, out of breath, out of stock
✅ The lift is out of order again.
✅ This map is out of date.
Phrases with "at"
at first, at last, at least, at once, at the moment
✅ At first I didn't like it, but now I love it.
✅ At last, the bus arrived!
Confusable pairs
| on time | punctual — exactly at the scheduled moment |
| in time | early enough — before something starts |
| at the end (of...) | at the final point of something specific |
| in the end | finally, eventually |
Common mistakes
| ❌ | ✅ |
|---|---|
| We went to work in foot. | We went to work on foot. |
| At the end, we agreed. (meaning eventually) | In the end, we agreed. |
| The bus was by time. | The bus was on time. |
| I'm on a hurry. | I'm in a hurry. |
| The machine is off order. | The machine is out of order. |
Frequently Asked Questions
What is the difference between 'on time' and 'in time'?
'On time' means punctual — exactly at the scheduled moment: 'The train left on time.' 'In time' means early enough — before something starts or before it is too late: 'We arrived in time for the film.' 'On time' = punctual; 'in time' = not too late.
What is the difference between 'at the end' and 'in the end'?
'At the end (of something)' refers to the final point of a specific thing: 'At the end of the book, the hero wins.' 'In the end' means 'finally' or 'eventually', after a long process: 'In the end, they decided to stay home.' 'At the end' usually needs 'of'; 'in the end' stands alone.
Why don't fixed prepositional phrases follow rules?
Fixed prepositional phrases are idiomatic — the preposition is set by convention, not by a logical rule. 'On foot', 'by heart', 'in a hurry', and 'out of order' cannot be worked out from the general meaning of the prepositions. They must be learned as whole units, the same way you learn vocabulary.
What does 'by chance' mean?
'By chance' means accidentally, without planning — something that happens unexpectedly: 'I met an old friend by chance.' It is close in meaning to 'by accident', though 'by accident' often suggests an unwanted result, while 'by chance' is neutral.