Sentence 1: Donovan decided to build a robot. 
 Sentence 3: He made a square head with an antenna 
 Sentence 4:  He added claw shaped hands 
 Sentence 5:  The finished robot could walk and talk 
 Option 1: He realized he it is too expensive and he could not afford it. 
 Option 2: He went to the hardware store to buy parts.