in addition 是一个副词性短语,通常用于句首或句中,表示“此外”、“而且”,后面常接逗号,引出额外的信息。
in addition to 是一个介词短语,后接名词、代词或动名词(即动词的 -ing 形式),表示“除了……之外(还)”。
in addition 是副词短语;in addition to 是介词短语。in addition 后面不能直接跟宾语;in addition to 必须后接宾语(名词/代词/动名词)。in addition 常用于句首或独立使用;in addition to 通常位于句中引导一个介词短语。❌ 错误:In addition playing the piano, he also sings.
✅ 正确:In addition to playing the piano, he also sings.
❌ 错误:She likes reading in addition books.
✅ 正确:She likes reading in addition to books. (但更自然的说法是:In addition to books, she likes reading.)