Student or Learner
I wonder what is the difference between following sentences:
"I see children playing in the park." and "I can see children playing in the park."
"I hear music in the flat opposite mine." and "I can hear music in the flat opposite mine."
Does the verb "can" mean that the perception is continues while the present without "can" mean a short period of time?
We do not normally use continuous forms for the verbs of perception in their literal sense; we use can (when we would use a continuous form with other verbs): I can see children / I can hear music now, as I speak.
Note that we can use the continuous form for these verbs when they have a different meaning, or when the perception is not usual:
Are you still seeing Emma? = going out with her.
I must be tired. I am seeing spots before my eyes.
I'm going mad. I'm hearing things that aren't there.