怎么区分谓语动词和非谓语动词

1、谓语动词：在句中用作谓语，在形式上要与句中主语在人称和数上保持一致。He wants to buy a new bicycle.

2、非谓语动词，它包括动词不定式、咿蛙匆盗动名词、现在分词和过去分词，这些动词形式皆不能单独用作谓语，它们在句中可用作主语、宾语、表语、定语、状语、补语等。He wants to buy a new bicycle.（不定式）I'm very sorry for having to bother you.（动名词）