Clases Españols

I am trying to learn Spanish, under the patient tutelage of the maintenance guy who does the rounds in our office every night. I always used to say hello to him, and he would wave back. At some point he told me his name and asked mine, and then he said "Como esta?" so I said "Bien, gracias" and he lit up with smiles. I told him that's really all the Spanish I know, but I would like to learn more.

Now when he comes by on his rounds, he spends an earnest few minutes every day conducting a one-sided conversation with me. He comments on the weather, identifies the office supplies on my desk, inquires how my day went, etc. I can usually understand what he's saying, but I can't formulate a reply - I don't know how to conjugate verbs or anything. Actually I don't know any verbs. Yesterday he flipped through a newsletter about dairy cattle management that was on my desk, and pointed out "vaca", "vaca," "caballo," etc. I pointed at a picture and said, "Vaca." Alas, it was a bull. He almost fell over laughing. "No es vaca!" wiping the tears from his eyes.