I'm totally confused about the usage of left and remain- in many situations.
For example, when talking about the quantity of the classes that I have to take today after I took one class already and I'm not sure how many more classes we I have today, then I'm going to ask my friend:
How many classes are left today?
How many classes remained / remains today? (or maybe do remains, or did remain)
When asking about quantity of a product:
How many eggs (are?) left in the refrigerator?
How many eggs remained / remains in the refrigerator?
What's the proper way to use them?
N.b. editing addition: should we not use auxiliary verb with remain as we do with left (both: in passive voice and present progressive)? I mean to something like "How many eggs do remain in the refrigerator?" If we shouldn't, then what's the difference between left and remain, here are both verbs, and why do we use auxiliary verb just in case of 'left'?