Mine has two knobs one for each wiper. The left knob for the left,etc.
As for washers it is common that the hoses are shot, or the nozzles are plugged up or both.
Go under your hood and find where the rubber hoses tee together, and then go into the bottle. If you disconnect the tee, and have someone press the washer button, it might spray some out of the line. You can isolate where the problem is. If it does shoot out some, then you know the nozzle or hose endis plugged and compressed air might clean it out. If not the pump may be shot. See if it makes a sound when it is supposed to be pumping. Mine has bad hoses. I bought a long squeegee and keep the windows pretty clean with that. The washers were low on my to do list.....and after 3 years I haven't gotten to them yet