No. As explained in the course notes, mi in this pattern (also fe in some areas) is an optional particle that can be used before a positive verb. It is more commonly used in some dialects than others, sometimes routinely, sometimes only for emphasis, in other dialects not at all.
If mi/fe is used, it causes a soft mutation.
No. See the pronunciation videos that we recommend in the notes - look on the web for 'youtube Welshplus pronunciation basics'.
- the letter ff as in English 'off'
- the letter f as in English 'of'