Essays are always formal.
'Dad' in Finnish is 'isä', 'iskä or 'isi'. 'Isä' is the formal one.
Otousan is someones father. Chichi is referring to your own [My dad] there are other sayings, more or less formal: informal: papa, tousan formal: otousan, chichi
Tu/usted y mi padre (informal/formal 'you')
It is generally best to avoid using idioms in formal essays as they can be seen as too casual or informal. It is more appropriate to use formal language and clear, concise expressions to convey your message effectively in an academic or formal setting.
formal
yes they are used in magazines
Rose Adelaide Witham has written: 'Essays of today, informal and formal' -- subject(s): American essays, English essays
Since this is informal useage, papá. You could say padre, but that is more formal.
introductory paragraph
Mon Pere is My father Mon Papa is My dad But if your doing a school assignment I suggest using Mon Pere because it is more formal =]
introductory paragraph.