Refuting Information and Opinions

Cautious Approach

لا أوافق على ذلك I do not agree with that. 

لم أعد هذا I won't second that

البعض يعتقد أنّ... ولكن لا أوافق هذا الرأي Some believe that... but I do not agree with this view...

لا يصدر عن شخص مطلع على these words don't come from someone knowledgeable about

فهذا صحيح من بعض الوجوه ولكن this is true in some respects but

لو سلمنا بهذا الرأي... فإن ذلك سوف If we accept this view... than this will... This statement is good if you want to lead into a longer analytical statement.

عندي ألف تحفظ وتحفظ على I have 1001 reservations about

أحسب ألف حساب ل I have 1000 apprehensions concerning

نعيش في واد ويعيشون في واد We live in one wadi and they live in the other. We are poles apart. Let's agree to disagree. 

لا يكاد يكون لها علاقة ب there is hardly a relationship with...

Critical Approach

لا علاقة له ب there is no relationship with

هذا حق يراد به باطل this is a truth used to cover lies

لا أساس لها من الصحة has no basis in truth, baseless

لا يستند إلى أساس عملي ومنطقي is not based on the practical or logical foundation

بعيد كل البعد عن a far cry from

لا شيء أبعد عن الحقيقة من ذلك nothing is further from the truth than that

لا توجد ذرة من حقيقة في there is not a grain of truth in

أسمع جعجعة ولا أرى طحنا Much ado about nothing (lit: I hear the grinding of millstones yet I see no flour). This expression is a good way of highlighting the insignificance of a perceived problem.

Combative Approach

هيهات أن preposterous 

ما هذه الترهات What is this nonsense? What is this B.S.?

كلام فارغ bunk, nonsense

كلام مجتر ridiculous talk

كلام مرسل empty rhetoric

كلام مبتذل trite, stupid talk

الخطاب الطفولي childish discourse

لا تستبق الأحداث don't jump to conclusions!

لا يعرف الكوع من البوع he is clueless. Literally, he does not know his elbow from the bend in the road. 

مثل الأطرش في الزفة Like a deaf man at a wedding. Used to describe someone who doesn't know anything.

حبل الكذب قصير The rope of lies is short. 

أكذب من مسيلمة A bigger liar than Masaylmah. A really big liar, the saying is in reference to a false prophet during the time of the Prophet Mohammed. Not in common usage but it is understood. I have read it a few times in relation to corrupt political regimes.

الكذب داء والصدق دواء Lying is a disease and truth is the cure.

يأكل على كل الموائد He eats from every table. He is a major hypocrite.