Complete Sentences Exercise. A sent ences is a group of words which expresses a complete thought. It begins with a capital letter and ends with a period. For example : walked into the home This is not a complete sentences because it does not tell who walked in. Therefore a line should be drawn through it. Other example : the boys walked into the house This expresses a complate thougt so it should begin with a capital and end with a period. The boys walked into the house. 1. when the doorbell rang 2. the boys went fishing 3. and ran to the window 4. went down the street 5. suddenly a voice 6. the cop on the corner 7. my mother turned on the light 8. turned on the light 9. soon the bell rang 10. running down the path