based

/beɪst/ (bre, ipa) · /beɪst/ (ame, ipa) · /ˈbāst/ (ame, mw)

based — adjective

1. If something is based on something else, it uses that thing as its starting poin

1.形容詞B1
釋義

If something is based on something else, it uses that thing as its starting point, main idea, or source material.

例句

Lakshmi's novel is based on true events from her grandmother's childhood.

based on [source material]

The board's final decision was based upon a careful review of all the evidence.

based upon [formal alternative]

同義詞
  • founded on

    Emphasises the idea of being built upon a strong foundation, often for institutions or abstract concepts

  • derived from

    Focuses on the idea of coming from a source, typically for words, substances, or data

  • grounded in

    Suggests a deep, solid connection to facts or principles; more formal

反義詞
  • unfounded

    Describes a claim or idea that has no basis at all — opposite of being supported by evidence

文法句型

based on [noun/phrase]

based upon [noun/phrase]

用法筆記

Always followed by 'on' (or 'upon' in more formal English). Cannot be used directly before a noun — 'a based-on-facts report' is incorrect; use 'a report based on facts' instead.

常見錯誤

❌The movie was based of a true story.
✅The movie was based on a true story.
💡Use 'on', not 'of', after 'based'.
❌This is a based-on-research paper.
✅This paper is based on research.
💡'Based on' cannot be placed before a noun like a single adjective.

2. A particular place serves as a person's or organization's main home, office, or

2.形容詞B1
釋義

A particular place serves as a person's or organization's main home, office, or center of operations.

例句

Valentina is based in Taipei but travels to Hong Kong every month for work.

based in [city] for a person's work location

The charity's main office is based at a small building near the university hospital.

based at [specific address/location]

同義詞
  • stationed

    Used especially for military personnel or workers who are assigned to a specific location

  • situated

    More formal; describes the physical location of a building or organization

文法句型

based in [location]

based at [specific location/address]

用法筆記

Followed by 'in' for cities, countries, or regions, and by 'at' for specific addresses, buildings, or institutions. Cannot be used before a noun — 'a based-in-Tokyo firm' is incorrect; write 'a firm based in Tokyo'.

常見錯誤

❌Our team is based at London.
✅Our team is based in London.
💡Use 'in' for cities and countries; use 'at' only for specific addresses or buildings.
❌She is a based-in-New-York journalist.
✅She is a journalist based in New York.
💡'Based in' cannot go before the noun.

3. Containing a particular substance or having a particular feature as a main or im

3.形容詞B2
釋義

Containing a particular substance or having a particular feature as a main or important part.

例句

Many builders now prefer water-based paints because the smell is much lighter.

[noun]-based = made of / containing

The school uses a project-based learning method where students complete real tasks.

同義詞

文法句型

[noun]-based

用法筆記

Typically used as a compound adjective placed before a noun, formed by adding '-based' to a noun. When placed before the noun, a hyphen is usually added (e.g., 'water-based paint', 'fact-based argument'). This sense can also appear after the noun with no hyphen: 'paints that are water based'.

常見錯誤

❌A water based paint is easier to clean.
✅A water-based paint is easier to clean.
💡Add a hyphen when the compound adjective comes before the noun.
❌Oil based paints smell stronger.
✅Oil-based paints smell stronger.
💡Same rule: hyphenate before a noun.