有効

yūkō
adjective★Intermediate— valid, effective, in effect
formal

Valid, legally binding, or officially recognized

この契約は有効です

This contract is valid

💡

Often used in legal or formal contexts

general

Effective, producing the desired result

この方法は有効です

This method is effective

💡

Common in everyday language to describe usefulness

general

In effect, currently active or operational

このルールは有効です

This rule is in effect

💡

Used to describe rules, systems, or conditions that are currently active

Collocations

有効な手段effective means有効期限expiration date有効な証明valid proof

Related Phrases

有効期限phrase
expiration date
有効な手段phrase
effective means

💡Pro Tip

Common Usage

'有効' is often used in formal and legal contexts, but it's also common in everyday language to describe effectiveness.

⚡Gold Rule

Legal Context

In legal contexts, '有効' means 'valid' or 'legally binding'.

📖Word Origin

From 有 (yu, 'to have') + 効 (kō, 'effect, efficacy')

📝Usage Notes

Can be used as a na-adjective (有効な) or as a noun (有効)

Word Breakdown

有
to have
root
+
効
effect, efficacy
root
和英辞典