Expressing opinion
To argue,
allege, assert, assess, be convinced, believe, consider, feel, hold,
judge, maintain, opine, suggest, think + that/as
To criticise
Assertion,
assessment, belief, conviction, judgment, opinion, position, suggestion, view
To hold
opinion
is of the
opinion that
according to
as far as …
is concerned
Expressing
facts
Confirm,
demonstrate, establish, identify, indicate, make clear, note, observe, point
out, prove, show.
Neutral
Conclude,
emphasise, mention, say, state, stress and write.
Source: https://guinlist.wordpress.com/2015/06/15/107-the-language-of-opinions/