Answer:
Coalition governments in parliamentary systems become necessary when there is no clear majority in Parliament.
Step-by-step explanation:
A coalition government is a collaboration of ministers and state secretaries from two or more political parties who form a government on the basis of a majority of seats in parliament.
Government coalitions occur in almost all countries where parliamentary representation is elected through the system of proportional representation, whereby none of the participating political parties can rule alone on the basis of a majority vote.