dual
dual — adjective
1. having or consisting of two separate parts, functions, or aspects that work toge
having or consisting of two separate parts, functions, or aspects that work together as one — for example, a kitchen tool that both chops and grinds, or a manager who also handles customer service.
Chiara bought a sofa with a dual function — it folds out into a bed.
dual function / dual purpose
The new phone has a dual camera that takes wide and close-up shots.
Naoko's dual role as editor and translator keeps her schedule very full.
The gym offers a dual membership that covers both the pool and the fitness centre.
- single
having only one part or function
文法句型
dual + noun
用法筆記
Only used before a noun. Cannot follow linking verbs (e.g. not 'the role is dual').
常見錯誤
2. referring to a car or van that has two identical sets of driving controls — the
referring to a car or van that has two identical sets of driving controls — the learner operates the main set while the instructor can use the second set to intervene when necessary.
Driving school cars have dual controls so the instructor can brake from the passenger side.
dual controls in a learner vehicle
Quan passed his test quickly because he practised in a car with dual controls.
Most driving instructors insist on dual-control cars for safety during lessons.
Sivan felt much safer during her first lesson knowing the car had dual pedals.
文法句型
dual-control + noun
dual + controls/pedals/brakes
用法筆記
Almost always appears before 'controls', 'pedals', or 'brakes'. The compound form 'dual-control' (with a hyphen) is common before other nouns like 'car' or 'vehicle'.
3. having the legal right to be recognised as a citizen of two nations simultaneous
having the legal right to be recognised as a citizen of two nations simultaneously, carrying the privileges and duties of each.
Bilal holds dual citizenship in Canada and Lebanon through his parents.
dual citizenship / dual nationality
Some countries, such as Japan, do not let citizens hold dual nationality after age twenty.
Lucía applied for dual British and Spanish citizenship after five years in London.
Felipe discovered that having dual citizenship made travel between his two home countries much easier.
- single nationality
citizenship of only one country
文法句型
dual + citizenship/nationality
用法筆記
Used exclusively with nouns meaning citizenship or nationality. Not used for other kinds of double belonging (e.g. not 'dual club membership' in this sense).
dual — verb
1. to widen or upgrade a single-carriageway road by adding a second lane in each di
to widen or upgrade a single-carriageway road by adding a second lane in each direction and a dividing barrier down the middle, so that traffic moving opposite ways is separated.
The local council plans to dual the main road to reduce traffic jams.
dual as a transitive verb (chiefly UK)
The A12 was dualled last year, cutting the journey time by fifteen minutes.
The government spent millions to dual the highway linking the two port cities.
Campaigners are calling for the dangerous rural road to be dualled as soon as possible.
- widen
more general; 'widen' does not specify adding a central barrier or creating a dual carriageway
文法句型
dual [a road]
be dualled
用法筆記
Chiefly used in British English. The passive form ('the road was dualled') is more common than the active. The subject is typically a government body or transport authority.
dual — noun
1. a grammatical category, found in some languages, that is used when referring spe
a grammatical category, found in some languages, that is used when referring specifically to two people or things — as distinct from the singular (one) and the plural (three or more).
Ancient Greek uses the dual for pairs of things, such as eyes or hands.
grammatical number for pairs
The dual is a rare feature in modern European languages, but it survives in Slovenian.
Sanskrit has a well-developed dual that appears on nouns, verbs, and pronouns alike.
Students of Arabic must learn the dual because it affects how verbs agree with subjects.
文法句型
the dual
用法筆記
Uncountable — use 'the dual' to name the category itself. Contrast with noun sense 2, which refers to a specific word or ending within that category.
2. a specific word, suffix, or grammatical ending that expresses the dual number in
a specific word, suffix, or grammatical ending that expresses the dual number in a language that has this category — for example, the suffix that marks a noun as referring to two items.
In Arabic, the suffix '-āni' is a dual attached to masculine nouns.
countable instance of a dual form
Linguists compare how duals in different languages handle noun-adjective agreement.
The Old English dual 'wit' meant 'we two' and was a distinct pronoun form.
Slovenian duals are still used in everyday speech, not just in formal writing.
文法句型
a dual
duals (plural)
用法筆記
Countable — a single word or morpheme can be called 'a dual'. Use plural 'duals' when discussing multiple such forms across or within languages.