Need polite phrases expressing disagreement with the information/conclusions of another person, especially an educator [closed]

My classmate told me I should always say, "With all due respect," or "I politely disagree," when disagreeing someone - especially an educator - in order to avoid being perceived as rude.

For example:

Teacher: This class always infuriates me. Most of you are either absent or late for my class. I will give you all failing grades in this subject!

Me: With all due respect Ma'am, many of my classmates actually do attend your class, and arrive early, to learn something about your subject. I think you should take all those students who attend your class on time and daily, into consideration.

or

Teacher: There's a higher incidence of suicide in men than women because men choose to hide their suffering or pain without telling anybody.

Me: Ma'am, I politely disagree with this opinion. According to the most recent studies of the American Psychiatric Association about suicide, more women attempt suicide than men, although men seem to be more successful in their attempts, resulting in more fatalities.

Can you suggest some polite variations?

Solution 1:

Beg to differ

a polite way of saying that you disagree with something that someone has said

I beg to differ with Mr Stahl's final assertion.

Although I should note that I don't hear this much and depending on how you say it you could come off sounding condescending.

Solution 2:

The ones you've listed are fine; depending on what circles you're in, the more straightforward "I disagree." could come off as more sincere (as long as your tone of voice is polite -- I come from the school of thought that it's more important to be respectful than to declare that you will be). Another option, if it's a disagreement of opinion rather than fact, you could say "The way I see it is..."

Solution 3:

There's a group of phrases that can soften the disagreement by conceding, "you may be right" or "I may be wrong" :

"That may be the case, but..."

"You might not agree with me, but..."

"I may be mistaken, but..."

...or preparing the interlocutor for a possible disappointment:

"Now don't take this the wrong way, but..."