Free indirect discourse (FID) can be defined as a mode of speech and thought representation which relies on syntactic, lexical and pragmatic features. On the syntactic level, passages of FID are constituted by non-subordination and (if applicable) temporal shifting in accordance with the basic tense of the report frame.
Orlando WALKED through the house with his elk hounds following and FELT content. He had matter now, he THOUGHT, to fill out his peroration. Perhaps it WOULD be well to begin the speech all over again. (Virginia Woolf, Orlando)
Since the frame is in the past tense (walked), the verbs in Orlando's thoughts rendered in FID need to be aligned …
Fludernik, Monika. "Free indirect discourse". The Literary Encyclopedia. First published 20 October 2001
[https://www.litencyc.com/php/stopics.php?rec=true&UID=444, accessed 23 February 2019.]