さいです is for people or animals only.

Introduction

‘years old’ in Japanese is さいです. For example, ‘I am 5 years old‘ is 私は五さいです。

You need to remember that さいです is used only to describe the age of people or animals. It is not used for other things such as building.

Example

Task: Change into Japanese.

• Tokyo Tower is 35 years old.

Answer

Incorrect

• 東京タワーは三十五さいです。

Correct

• 東京タワーはできてから三十五年です。

  (It is 35 years since Tokyo Tower was built.)

• 東京タワーはできてから三十五年がたちます。

  (35 years have passed since Tokyo Tower was built.)

• 東京タワーは三十五年のれきしがあります。

  (Tokyo Tower has a 35 year old history.)