Is the following sentence not so good?
As I have mentioned from time to time, English is just one of our tools
for communication.
If we use "from time to time" in the above, should we use "As I mention
from time to time"?
David
Depends.
If you are through with the habit of mentioning it from time to
time (or wish to be non-committal about the prospect) then use the first.
If you expect to continue doing so and feel it is important to allow
for that possibility then use the second.