Happen is not a participle. It is the simple present tense. The present participle is happening, and the past participle is happened.
The past participle of a verb is a verb ending in -ed that acts as an adjective or an adverb.For example:The clear blue sky seemed to turn into a darkened cloud once winter began.Therefore, the past participle of happen is happened.
A participle dangles when the participle phrase is not sufficiently close to the word that the participle (or participial phrase) modifies. If the participle is the first element in a sentence, the modified word should be the next word. The most egregious example of a dangling participle occurs when the word modified does not even occur in the same sentence as the participle, as in "Sitting in my chair, numerous events occurred".
Being is the present participle. The past participle is been.
The past participle of do is done. The past participle of have is had.
The present participle is beating. The past participle is beat.
Present participle - winding Past participle - winded
The present participle is "sowing" and the past participle is "sown".
Begun is the past participle, and beginning is the present participle.
The past participle of am is been. Not does not have a past participle
The present participle is swelling. The past participle is swelled.
The past participle is proceeded. The present participle is proceeding.
The past participle is "seen", and the present participle is "seeing".