ok, three questions:
1) can i convert players' positions by consatntly playing them in a certain position?
for example, can i make nocerino a DM rather than CM, chiellini a CB and salihamidzic a RB?
2)is it good to change formations often, depending on the opponent, or does the team do better when you stick to one formation?
3) how do i get players to tutor other players?
1) First you must tell the coach to train the player in a new position, then as you play him regularly in that position he will become stronger and it will turn into his position.
2) Obviously if you keep a 4-4-2 for the whole season the team will play better with it, as it will be used to the style of play, but over time the opposition learns how to counter your formation, so you have to change it slightly. Against lesser teams, i used to play with 3 strikers, while against Milan Inter etc used to play with 2 strikers. I changed my midfield pairing a lot due to fatigue and also due to the opposing teams midfield. For example i very rarely played Zanetti, only against Roma, Fiorentina, Inter and Milan, as they have true AMC's like Kaka, Totti, Stankovic etc.
3) through Player Interaction.