essential

essential — adjective

1. needed so much that a particular activity, situation, or process cannot succeed

1.形容詞B1
釋義

needed so much that a particular activity, situation, or process cannot succeed or continue without it.

例句

A passport is essential when you travel to a foreign country.

essential when + clause

It is essential that Noor reads the safety instructions before starting the machine.

it is essential that + clause

同義詞
  • necessary

    more general and neutral; 'essential' is stronger

  • vital

    suggests something is needed for life or continued existence

  • crucial

    emphasises that a specific outcome depends on it

  • indispensable

    the strongest; nothing can replace it

反義詞

文法句型

essential for [noun/phrase]

essential to [noun/phrase]

it is essential that [clause]

it is essential to [verb]

用法筆記

Can be followed by 'for' (emphasising the goal), 'to' (emphasising the connection), a that-clause, or a to-infinitive. The that-clause often takes a subjunctive verb (no -s on third person).

常見錯誤

A dictionary is important for my English class.
A dictionary is essential for my English class.
💡'important' means it matters a lot; 'essential' means you cannot succeed without it.

2. describing the basic nature or character that makes something or someone what th

2.形容詞B2
釋義

describing the basic nature or character that makes something or someone what they truly are, without which they would be different.

例句

The essential difference between the two libraries is their opening hours.

attributive: essential + [noun]

Honesty is an essential quality in any good friendship.

同義詞
  • fundamental

    suggests something forms the foundation of a system or idea

  • basic

    simpler and more common; less formal

  • inherent

    emphasises that it naturally belongs to someone or something

反義詞
  • secondary

    less important, not part of the core

  • superficial

    relating only to the surface, not the real nature

文法句型

essential [noun]

essential to [noun]

用法筆記

Usually placed directly before a noun (attributive position). When used predicatively with 'to', the meaning is closer to 'forming a basic part of' rather than 'absolutely necessary'.

常見錯誤

Food is an essential part of survival.
Patience is an essential quality of a good teacher.
💡In the first sentence, 'essential' means 'necessary' (sense 1). In sense 2, 'essential' describes a defining characteristic, not a practical need.

essential — noun