Third-person singular simple present indicative form of doubt.(verb)
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Use "doubts" in a sentence
""No one doubts but that he will do it" is incorrect, for it contains three negatives -- _no_, _doubts_, and _but_."
""My doubts on this subject are nothing more than _doubts_; they do not amount to a confirmed _unbelief_; because they admit the possibility of the account's being true."
"To ask the question or express any doubts is to mark one as a heretic."