back up
back up — phrasal verb
- back upbase form
- backs up3rd person singular
- backing up-ing form
- backed uppast simple
1. to move backwards, or to make a vehicle move in reverse
to move backwards, or to make a vehicle move in reverse
Sofie backed the taxi up slowly so the ambulance could pass on the narrow street.
transitive + particle: backed the taxi up
The lorry driver checked his mirrors carefully before backing up to the loading bay.
intransitive: backing up
Kian asked his passenger to watch the rear while he backed the van up into the garage.
Manuela reversed out of the driveway, then stopped and backed up to shut the gate.
The car in front of us suddenly backed up without giving any warning signal.
- advance
formal opposite; move ahead
文法句型
back up
back something up
back up something
常見錯誤
2. to give help, encouragement, or practical support to a person, group, or plan, e
to give help, encouragement, or practical support to a person, group, or plan, especially by showing public agreement or readiness to assist
Madison's teammates backed her up when she complained about the unsafe training conditions.
transitive: back + person + up
Kabir asked his older brother to back him up during the difficult conversation with their landlord.
The local council backed up the residents' plan to turn the empty lot into a community garden.
Hana promised to back up her younger sister at the school meeting with the headteacher.
The two security guards always backed each other up during the night shift.
文法句型
back somebody up
back something up
用法筆記
Common in both informal conversation and professional settings. The object can be a person, a group, an idea, or a plan.
常見錯誤
3. to show that a statement, story, or claim is true by providing evidence or by re
to show that a statement, story, or claim is true by providing evidence or by repeating the same account
The bank records backed up Mert's explanation of where the money had come from.
transitive: evidence backs up a claim
Kemi's account of the accident was backed up by three independent witnesses who saw the whole thing.
passive construction: was backed up by
Alessia found old receipts that backed up her tax claim from two years earlier.
The scientist could not back up his theory with any data from controlled experiments.
Eli told the headteacher what happened, and his best friend backed him up when questioned.
- substantiate
more formal; preferred in academic and legal writing
- corroborate
formal; used especially when a witness's account is supported by other evidence
- verify
implies checking the truth against a standard or reliable source
文法句型
back something up
back up something
back something up with something
用法筆記
Frequently used in formal, academic, and legal contexts. The passive form ('be backed up by evidence/data/witnesses') is especially common in journalism and research writing.
常見錯誤
4. to make a copy of computer data or digital files so that the information can be
to make a copy of computer data or digital files so that the information can be recovered if the original is lost, damaged, or deleted
Mayumi backs up her entire photography collection to a cloud service every month.
regular action: backs up + object + to + destination
The school's IT administrator backs up all student records at the end of each term.
Beatrix lost six months of work because she had never backed up her research files.
Before you install the new operating system, make sure you back everything up.
The company backs up customer data on three separate servers in different locations.
文法句型
back up something
back something up
用法筆記
The separable form ('back your files up') and the non-separable form ('back up your files') are both correct. The direct object should be files or data, not the device itself.
常見錯誤
5. if traffic or a line of vehicles backs up, the vehicles form a long, slow-moving
if traffic or a line of vehicles backs up, the vehicles form a long, slow-moving queue because the road ahead is blocked or there are too many of them
Traffic backed up for nearly five kilometres after the lorry spilled its load on the motorway.
intransitive: traffic backs up
Cars began to back up along the high street as the Saturday market got underway.
The accident on the bridge backed traffic up all the way into the neighbouring town.
Vehicles backed up at the border checkpoint while officers searched each lorry.
- clear
as in 'the traffic cleared after an hour'
文法句型
traffic backs up
something backs up
back something up
用法筆記
The intransitive form (traffic/cars back up) is much more common. The transitive form (an accident backs traffic up) appears mainly in news reports about road incidents.