sincerity?

[bosun]

How do you describe this kind of student who is always hardworking, eager to learning things and never miss or be late for class. can i say he
/she is sincere student? or can i say the good student has sincerety.

 

[Siberia]

I would use 'diligent'.

 

[cuchuflete]

A sincere student may be sincerely dedicated to things other than paying attention in class. I think the word you are seeking is diligent.

 

[SweetSoulSister]

I would say a "diligent" student.

I think "sincere" is a compliment, but it sounds like he/she is a nice person, in terms of character. But you might get other opinions about that.

EDIT: That's 3 natives for "diligent".

 

[DCPaco]

I would say that in the context of learning, this is an exemplary student.

If you are looking for one word, I believe it may be "devotion" and as an adjective: devout.

de·vo·tion n.
1. Ardent, often selfless affection and dedication, as to a person or principle. See Synonyms at love.
2. Religious ardor or zeal; piety.
3. a. An act of religious observance or prayer, especially when private. Often used in the plural.
b. devotions Prayers or religious texts: a book of devotions.

4. The act of devoting or the state of being devoted.

Also, zealot and zealous...but these are sometimes used as qualifiers that are both admirable and excessive.