Is it you have a dream or you had a dream?

Answer 1

Both. The kind of dream Luther King had was not the kind of dream Richard II had before the Battle of Bosworth. The former, in articulating his vision, can say, "I have a dream". Those narrating dreams after waking say, "I had a dream". The interesting question is what determines the use of the past tense in the latter case. So-called Lucid dreamers claim that it is sometimes OK to realize or assert in sleep, "I Have a Dream". Others think that they dreamt that they realized or asserted this. How would that dispute be settled - and what hangs on it? This anonymous note is by Roger Squires

Answer 2

It is "you had a dream," as the verb "had" is the past tense form and is used to indicate an action that occurred in the past.