Mar7aban! Qad has two meanings. One when used in the past, and one when used in the present. In the present, it means something "may", or "might" happen. For example, 'Qad yekoun jayyed' = It might be good. Or, 'Qad edh-heb' = I may go. In the past, it has almost the opposite meaning; it means something "definitely" happened. It is emphatic in the past tense. For example, 'Qad qala' = He (definitely) said. Or, 'Qad dhehebtu' = I (in fact) went. 'Qad' can be used (in theory) with any verb in the past or present tense, to mean either "definitely happened" or, "might happen".