1. SIMPLE PRESENT NEGATIVE FORM Don’t – doesn’t PRESENTED BY GIANNY ORTIZ

2. Let´s remember! Caterpillar develops and builds four- stroke- cycle diesel engines. The block houses many components. The liners form the combustion chamber. The compression rings seal the bottom of the combustion chamber of the cylinder. Oil rings control the oil film on the walls of the cylinders.

3. Subject (he, she, it) + verb + s + complement. Caterpillar develops diesel engines. Caterpillar = it

4. Subject (I, we you, they) + verb + complement. Oil rings control the oil film on the wall of the cylinder. Oil rings = they

5. Reading : “ Gas Engine Combustion Process” In a natural gas engine, compressed air does not provide enough heat for combustion to begin. An ignition module supplies a high voltage current to a spark plug that ignites the mixture. It creates combustion. It is a SPARK IGNITION COMBUSTION.

6. Simple Present Negative Form I don’t have a spark plug. You don’t use mechanical components. He She doesn’t work in the top of a mountain. It We You don’t drive the machine. they

7. Examples: doesn’t The piston doesn’t have rotary motion. The digital multimeter doesn’t work properly. The rocker arm doesn’t work.

8. Examples: don’t The pistons don’t have rotary motion. The crankshafts don’t make reciprocating motion. The rocker arms don’t work.

9. The mine doesn’t have cooper. It has coal.

10. You don’t contaminate the water.

11. You don’t drive a car. You operate a machine.

12. They don’t work in a factory. They work in a workshop.

13. I We You they Don’t

14. He She it Doesn’t

15. vocabulary Stroke: Carrera Bottom: parte inferior Top: parte superior, cima. Spark plug: bujía. Cooper: cobre Coal: carbón Enough: suficiente Much: mucho Many: muchos

16. Complete with don’t or doesn’t. 1.The intake valve _________ open at the compression stroke. 2.The cycle _________ start with the exhaust stroke. 3.The exhaust valves _________ remain closed at the exhaust stroke. 4.He ________ know the differences between gas and diesel engine. 5.They _________ clean the crankcase. 6.The mixture __________ contain much oxygen. 7.Gasoline _________ produce enough heat. 8.Diesel engines ___________ use spark plugs. 9.The water pumps __________ work properly. 10.Cat engines ____________ use the two stroke cycle.