The pair have linked up brilliantly this season to leave Manchester City out in front in the race for the title.
And Aguero, who joined from Atletico Madrid, said: "The football is quicker than in Spain, you have to run more and be more alert.
"I am forced to be more connected. The Spanish player David Silva is the one who has surprised me the most. He's top quality.
"He has real class and impressive vision, some of the passes he makes are truly amazing."