English translation:
from the fact that
Structure:
Verb + ことから
いAdj + ことから
なAdj + な / だった + ことから
Noun + の / だった + ことから
According to this video
This grammar is somewhat stiff. Should the 硬 symbol be added to it?
硬 is mostly used when it’s academic grammar, or stuff you would only find in literature or really old stuff. ことから can be found in spoken Japanese, where you never find 硬 grammar.