What's the past participle of "do"?

(a)  

What's the past participle of "cost"?

(a)  

What's the past participle of "go"?

(a)  

What's the past participle of "swim"?

(a)  

What's the past participle of "dress"?

(a)  

What's the past participle of "ride"?

(a)  

What's the past participle of "fall"?

(a)  

What's the past participle of "leave"?

(a)  

What's the past participle of "meet"?

(a)  

What's the past participle of "write"?

(a)  

What's the past participle of "sing"?

(a)  

What's the past participle of "think"?

(a)  

What's the past participle of "run"?

(a)  

What's the past participle of "teach"?

(a)  

What's the past participle of "mean"?

(a)  

What's the past participle of "read"?

(a)  

What's the past participle of "get"?

(a)  

What's the past participle of "cut"?

(a)  

What's the past participle of "steal"?

(a)