给定一句英文文本，将其中所有的动词（除了情态动词和助动词）用它们的现在分词形式替换。


She was singing a song while he was playing the guitar, and they were both enjoying themselves.
Replacing all verbs (excluding modal and auxiliary verbs) with their present participle form:


She was singing a song while he was playing the guitar, and they were both enjoying themselves.


Becomes:


She was singing a song while he was playing the guitar, and they were both enjoying themselves. (no changes needed as all verbs in the sentence are already in present participle form)