I have conected to PostgreSQL and imported the layer to QGIS.
The names of columns are written using English letters.
Can the names of columns be automatically renamed using another language?
Open the "Layer properties" and go to the "Fields" tab. You will see a column "Alias". Whatever you enter there will be used throughout the user interface.
I haven't tested this but perhaps this might help:
Settings > Options > Locale
The only other method I can think of is:
Add Vector Layer > Encoding
And select whichever one you think is suitable. Hope this helps!
I'm not sure if I understand you correctly but if You're trying to translate english names of columns into your local language automaticaly I think you can't do this in QGIS.
The only resolution that I mind is creating a view on database and show this view in QGIS
I'm only not sure if you can edit data via views, but if you only want to show it in QGIS this could be resolution.