Yes, email is also formal in the situation the content in the email is business critical and stakeholders or sponsor must have to Approve the content ....
In Rita's prep, it says that formal meetings and stakeholder briefings can be formal verbal though the video keeps meetings as informal verbal, is there a difference of opinion in th PM community?
Project Manager should equally be good in all 4 types of the communications.. PM spends most of the time with Project team so in that case Informal verbal & written will be mostly used..
A PM should be equally good in all types of communication but should prefer written communication as in verbal communication sometimes information gets lost or manipulated.