Translation:He used to speak to his grandmother every morning.
The translation for 'at pleje' as 'usually' is .. not a very fortunate one. 'Pleje' is a verb, of course, and should be treated as such, but the English language doesn't have a present form of 'used to'. You -could- translate the sentence like so, but I would recommend keeping the structure rather close to the given sentence.
The actual translation of 'usually', the adverb, is 'sædvanligvis', so you'd go with "Sædvanligvis talte han med sin bedstemor hver morgen."