How can you take advantage of this? A gratitude journal is an easy and actually pretty fun way to keep your attention trained on what’s important in life: all the beautiful, exciting and wonderful things that surround youday to day but which you may have forggten to appreciate.
The above contents come from the book The 21 Day of challenge happiness
As for the bold word, trained, is it a past participle? what is the grammatical facts of it?
According to my research, I think trained on is a past participle phrase which modifies attention. Is it true?