Iam your father and lam telling you, you........ Study now.
must / have to
Like Ahmed, I prefer "must" to "have to" here. I'd probably use "need to." Bassem, please note that "Iam" is incorrect; it should be two words: "I am." Also, when titling a discussion thread, do not use "grammar" or "choose," etc. Try to use a title that is descriptive of the thread. Here it could be "must or have to."
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