by — Five Key Uses
Chance/Accident · Transport · Passive · Next To · Difference — Complete Guide
by — Cinq Emplois Clés
Hasard/Accident · Transport · Passif · À côté de · Différence — Guide Complet
Master all uses of by: by chance/mistake, travel by car/train, done by someone, by = next to, and increased by 10%.
Maîtrisez tous les emplois de by : by chance/mistake, voyager by car/train, fait by quelqu’un, by = à côté de, et increased by 10%.
By is one of the most versatile prepositions in English. It describes unplanned events (by chance), how you travel (by train), who performed an action (painted by Picasso), a location (by the door), and a margin of change (increased by 10%).
By est l’une des prépositions les plus polyvalentes en anglais. Elle décrit des événements non planifiés (by chance), comment on voyage (by train), qui a accompli une action (painted by Picasso), une position (by the door) et une marge de changement (increased by 10%).
by chance / by mistake / by accident
by chance / by mistake / by accident
Use by + noun (without the or a) for unplanned events and methods. The opposite of by accident/chance is on purpose.
Utilisez by + nom (sans article) pour les événements non planifiés et les méthodes. L’opposé de by accident/chance est on purpose.
by + noun (no article) — events
by + nom (sans article) — événements
by + noun — methods
by + nom — méthodes
I didn’t take your umbrella on purpose. I took it by mistake.
Kate and James keep in touch mainly by email. · Can I pay by credit card? We hadn’t arranged to meet. We met by chance. (PAS by the chance)
I didn’t take your umbrella on purpose. I took it by mistake.
Kate and James keep in touch mainly by email. · Can I pay by credit card?
travel by car / by train — in a car — on a train — on foot
travel by car / by train — in a car — on a train — on foot
Use by + vehicle (no article) for general transport. Add my/the/a and switch to in (car/taxi) or on (bus/train/bike). Walking = on foot (not by foot).
Utilisez by + véhicule (sans article) pour le transport en général. Ajoutez my/the/a et utilisez in (voiture/taxi) ou on (bus/train/vélo). Marche = on foot (pas by foot).
by + vehicle (general)
in — car / taxi (specific)
on — bike / public transport
They came in a taxi. / We were on the 6.45 train. (specific → in/on)
Did you come by car or on foot? (on foot, NOT by foot) Jess goes to work by bus / by car. (général → by, sans article)
They came in a taxi. / We were on the 6.45 train. (spécifique → in/on)
Did you come by car or on foot? (on foot, PAS by foot)
passive + by (agent) · by vs with · a play by Shakespeare
passif + by (agent) · by vs with · a play by Shakespeare
by — the agent (who/what did it)
by — l’agent (qui l’a fait)
with — the instrument (tool used)
with — l’instrument (outil utilisé)
The door must have been opened with a key. (instrument → with, NOT by a key)
The door was opened by somebody with a key.
‘Who is this painting by?’ — It’s by Rembrandt. Have you ever been bitten by a dog? (agent → by)
The door must have been opened with a key. (instrument → with, PAS by a key)
The door was opened by somebody with a key.
‘Who is this painting by?’ — It’s by Rembrandt.
by = next to / beside
by = à côté de / près de
Come and sit by me. (= next to me)
She was standing by the window. · There’s a café by the river. The light switch is by the door. (= à côté de la porte)
Come and sit by me. (= à côté de moi)
She was standing by the window. · There’s a café by the river.
increased / won / missed by — showing a difference
increased / won / missed by — indiquer une différence
Carl won the race by five metres. (= he was 5m ahead)
I missed the bus by two minutes. · Helen won by two votes.
The new line will reduce journey time by two hours. Clare’s salary has increased by 10%. (= 10% de plus qu’avant)
Carl won the race by five metres. (= il était 5m devant)
I missed the bus by two minutes. · Helen won by two votes.
The new line will reduce journey time by two hours.
Choose: by mistake / by hand / by credit card / by chance / by email / on purpose.
Choisissez : by mistake / by hand / by credit card / by chance / by email / on purpose.
Put in by, in or on for transport.
Mettez by, in ou on pour le transport.
Complete with by or with.
Complétez avec by ou with.
Complete using by + the margin given.
Complétez avec by + la marge indiquée.
Frequently Asked Questions — by
Questions fréquentes — by
By car = general mode of transport (no specific car). In my/the/a car = a specific vehicle is identified. Rule: by + bare noun (no article) for general transport; switch to in (car/taxi) or on (bus/train/bike) when specific.
By car = mode de transport général. In my/the/a car = un véhicule spécifique. Règle : by + nom seul pour le transport général ; in (voiture/taxi) ou on (bus/train/vélo) quand spécifique.
By = the agent (who/what performed the action): bitten by a dog. With = the instrument (what was used): opened with a key. Test: person/animal/force → by; tool/object → with.
By = l’agent (qui/ce qui a accompli l’action) : bitten by a dog. With = l’instrument (ce qui a été utilisé) : opened with a key. Test : personne/animal/force → by ; outil/objet → with.
The fixed expression is simply on foot. All transport methods use by (by car, by bus, by train) but walking uses on foot. It must be memorised as a fixed phrase.
L’expression fixe est simplement on foot. Tous les modes de transport utilisent by, mais la marche utilise on foot. C’est une expression fixe à mémoriser.
By + a number expresses the gap between two values: won by 5 metres = his margin of victory was 5 metres. Common patterns: increase/decrease by X%; win/lose by X points; miss/be late by X minutes.
By + un nombre exprime l’écart entre deux valeurs : won by 5 metres = la marge de victoire était de 5 mètres. Schémas courants : increase/decrease by X% ; win/lose by X points ; miss/be late by X minutes.
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