Common law
Inquisitorial. Judges, not lawyers, ask questions and demand evidence. Lawyers present arguments based on the evidence the court finds.

Civil law
Adversarial. Lawyers ask questions of witnesses, demand production of evidence, and present cases based on the evidence they have gathered. 

Common Law

A lawyer in common law starts with the actual case and compares it with the same or similar legal issues that have been dealt with by courts in previously decided cases, and from these relevant precedents the binding legal rule is determined by means of induction.

A consequence of this fundamental difference between the two systems is that lawyers from the civil law countries tend to be more conceptual, 

Civil Law

The civil law is based on codes which contain logically connected concepts and rules, starting with general principles and moving on to specific rules. A civil lawyer usually starts from a legal norm contained in a legislation, and by means of deduction makes conclusions regarding the actual case. 

Lawyers from the common law countries are considered to be more pragmatic

Common law
To make rulings as consistent as reasonably possible with previous judicial decisions on the same subject; set precedent, referee between lawyers; decide matters of law and, where a jury is absent.

Most judges rarely inquire extensively into matters before them, instead relying on arguments.

Civil law
To establish the facts of the case and to apply the provisions of the applicable code.

Though the judge often brings the formal charges, investigates the matter, and decides on the case, he/she works within a framework established by a comprehensive, codified set of laws. The judge’s decision is consequently less crucial in shaping civil law than the decisions of legislators and legal scholars who draft and interpret the codes.