- Walking is good exercise.
- Walking is a good exercise.
- Walking is a good form of exercise.
I'd like to know the difference in meaning among these sentences. Thanks a lot.
In your examples, there is a progressive narrowing of focus as to why walking is beneficial beginning generally and becoming more specific
Walking is good exercise.
Walking is generally a healthy thing to do
Walking is a good exercise.
Walking is one of many different exercises which may also be healthy.
Walking is a good form of exercise.
It is low impact and aerobic as opposed to running which is high impact.