My pressure washer was running fine then bogged out.The person who lent it to me said dont worry about the oil it is fine, so i didnt check. I checked the oil and it was almost bone dry. So i filled it with oil but now it wont start, is it possible that the engine is siezed up or, can i get it running.

Check that the oil you have used is the correct viscosity (Thickness) If too thick, it may be overheating and stop the unit from working.

could be water in carb, take bowl off and use carb cleaner to flush main jet, also check water separator if one is attached.
also look at carb linkages to crank and oil pivot points.

sounds like the pump has an issue check for restrictions in the hose as well as the filters look for any oil leak at the pump itself

check the oil level and oil level sensor

SOUND LIKE FLOAT IS STICKING

Pressure washer oil

I took this picture of my power washer so it's easy to explain the oil.
The oil is different for engine and pump.

The pump oil is 20 or 30 weight non-detergent. SAE20 or SAE30 motor oil. The level of the oil comes up about half way. There is a plastic viewport on side of pump ... oil comes up half way on viewport.

The engine oil is 10W30 motor oil. It comes up about half way or a bit more on dipstick.

To remove oil from pressure washer, do not turn engine on it's side or turn engine upside down or motor oil will run into the carburetor. You might wonder how I know that. Afterward, the carburetor needs to be cleaned out.

To remove oil, you can tip engine to the side but not so much that oil runs up into top part ... to remove the rest of the oil, you can use a plastic hose

Check to see if the oil is overfilled first.

If the oil is at a normal level, the engine was probably overheated or ran low on oil.

It is also possible that the machine was tipped over and oil ran into the cylinder.

Oil level in pump and motor OK? Spark plug not fouled? Has it sat for a while - carb dirty? Running (loaded) throttle rpm not high enough?

It would be best to have an oil pressure check. Get a reading at both idle and at 1500rpms.
Could be oil pump or bearings.
Bill

Check fuel pressure. Pump may have crapped out. If pressure is good, clean and rebuild carb.