4. Grammar: Present and Perfect Participles

Look back at the previous mixed-up text explaining the principle of the seawater greenhouse. Find a sentence that means the same as the following sentence:

The seawater is first pumped to the top of the greenhouse and then trickles down the cardboard of the front evaporator. As it evaporates, it cools and humidifies the air inside the greenhouse.

If you selected the following sentence, you were correct:

Having been pumped to the top of the greenhouse, the seawater trickles down the cardboard of the front evaporator and evaporates, cooling and humidifying the air inside the greenhouse.

Now, look at the following analysis. You can see that the perfect participle is used to describe an event that happened before the action expressed in the main clause, while the present participle is used to talk about events happening at the same time or after the event expressed in the main clause.

Earlier event

Having been pumped to the top of the greenhouse,

Perfect participle

(v Čj odpovídá přechodníku minulému)

Main event

the seawater trickles down the cardboard of the front evaporator and evaporates,

Main clause

Later event

cooling and humidifying the air inside the greenhouse.

Present participle

(v Čj odpovídá přechodníku přítomnému)

 

The present participle was covered in Unit 2b in the AEL5 course, so you should be familiar with this grammar point. To be able to fully understand and use the perfect participle, further explanation is necessary. Find it in this grammar overview. After you have gone through the grammar overview, practise this grammar point in a general English context first by completing this task. Then see if you can distinguish between present, perfect and past participles here. After that, see how participles are used in an unbroken text. Finally, use perfect and present participles in a technical context here.