No, they cannot. You cannot ad "ly" to a verb, and that is what a participle is, a verb that acts like an adjective. It has "ing" in the present form, and "ed, en, n" as the past form. Here are two examples: Present participle - The running dog got away. Past participle - I accept a written aplolgy. Both sentences contain participle adjectives. Although the "ing" form is also the progressiv