For simple statements:
* 是 (shì) - This is the most common and general way to say "is". It's used in simple sentences like "The sky is blue." (天空是蓝色的)
* 为 (wèi) - This is less common but can also be used for "is" in certain contexts. It often indicates a state or condition.
For questions:
* 是 (shì) - This is also used in questions like "Is this your book?" (这是你的书吗?)
For specific situations:
* 叫 (jiào) - This means "called" or "named" and can be used to say "is" when introducing someone or something. For example, "This is my friend." (这是我的朋友。)
* 是 (shì) ... 的 (de) - This phrase emphasizes the subject and is often used to emphasize a specific characteristic or attribute. For example, "This is a red car." (这是一辆红色的汽车。)
Example Sentences:
* 今天是星期一。 (Jīntiān shì Xīngqīyī.) - Today is Monday.
* 他是一个医生。 (Tā shì yīgè yīshēng.) - He is a doctor.
* 这本书很有趣。 (Zhè běn shū hěn yǒuqù.) - This book is interesting.
Remember that the specific word for "is" will depend on the context of your sentence. It's always a good idea to look at example sentences to get a better understanding of how the word is used.