They usually will perform the same task several times before their supervisor, a more senior lawyer, allows them to do a more complicated version of that project or work without supervision. A junior lawyer's work will be reviewed by a senior lawyer whereas senior lawyers can accomplish their work without review.

For instance a junior prosecutor will start by observing a senior lawyer for a month or more, then proceed to prosecute simple crimes like misdemeanors (toilet papering a house, speeding), before they are allowed to prosecute more serious crimes where a jury trial would be necessary. A junior attorney will conduct jury trials with a more senior attorney many times before they finally conduct one alone.

It takes many years of tutoring and mentoring by a senior attorney before a new lawyer is ready to handle cases alone.