Successful people always Have two things. One determination and second sincerity.
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in the above sentence, two events happen, so we use "have" in the sentence.. because have is the best choice to keep the meaning of the original sentence
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While the verb to have has many different meanings, its primary meaning is “to possess, own, hold for use, or contain.”
Have and has indicated possession in the present tense (describing events that are currently happening).
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The verb have has the forms: have, has, having, and had.