In order for a student to develop the most natural technique, sense of piano touch and ear training from the start of their music / piano education, an instrument in good working order is required. It does not make much difference whether the piano is new or old, rented or bought – the most important element is that the person does not have to ‘fight’ the instrument and experience struggles during practice in addition to various demands of learning to play piano!
Commonly, beginner students use an electronic keyboard or digital piano for practice (due to affordability) – unfortunately many lessons are spent to correct improper technique and uneven piano touch (just to name a few). Furthermore, no matter how much time is spent exploring these skills, students cannot apply them in their everyday practice at home as they do not have the proper instrument to discover and apply these possibilities.
Generally an electronic keyboard or digital piano are okay for a beginners, however by the time student starts to approach pieces that require pedaling, technical evenness and dynamics – they should have a proper piano. Depending on the progress of the child this usually happens within the first year of starting lessons.
Please know, no matter what a salesperson tells you – digital piano is NOT like a real Piano! Think of it this way: a Hyundai does not look, perform or feel the same as a Ferrari… same applies to musical instruments.