Determining the presence of jinn is a complex matter and not something that can be easily concluded. In Islam, it is important to rely on sound reasoning and logical explanations before attributing any unusual occurrence to jinn. However, some signs that may indicate jinn presence include supernatural activities or disturbances that cannot be explained naturally, sudden unexplained illnesses or changes in behavior, or uncontrollable and unusual phenomena. It is recommended to consult a knowledgeable Muslim scholar to assess such situations.