Why is the imperfect used on the 1st person singular example in this lesson. Is it to imply that I used to seem him doing it regularly? Thanks, Greg

Hola Gregory

In this sentence:

Yo veía lo que él hacía. (I could see what he was doing.)

We translated it as "could see" instead of "used to see"  or "saw" because "veía" here can have two different interpretations. The first with "could" is implied despite us not using the modal verb "poder". However you can also say "Yo podía ver lo que él hacía" which is literally that.

I hope this clarified it.

Saludos

Inma