on/at/with my computer

[CarloSsS]

Can all of these sentences mean "I used my computer to do some work last night" without further context.

I worked on my computer last night.
I worked at my computer last night.
I worked with my computer last night.

 

[Mr_Ben]

I worked at my computer last night. I think this is the clearest.
I worked with my computer last night. This is still pretty clear.

I worked on my computer last night. This is clear only in context because the reader listener can parse the sentence two ways:

• I [worked on] my computer. --I repaired it.
  
• I worked [on my computer]. --I used my computer to do some work

Realistically though, these phrases all work and will rarely be misunderstood. I would say "I did some work on my computer last night," and that has the same ambiguity as the third sentence above. Sometimes you just rely on your reader/listener to have some common sense ("What do I look like, a hacker?"), but it doesn't always work.

 

[SoothingDave]

I would say "worked on" is the most common. Yes, it is potentially ambiguous.