First you need to note that "can" has special grammar rules.  It is a defective modal verb, it not used on its own but always with other verbs, and it doesn't have the full range of tenses.

In terms of meaning, there are three main uses:

1. Have the ability to do something
2. Be permitted to do something
3. Have the potential to do something

It is the third sense that is used in your example. A paraphrase would be "This study has the potential to give English learners..."  I don't see it as particularly euphemistic.

Contrast this with "This study will give English learners".  This alternative makes a certain prediction about the future. Whereas the "can" form only expresses potential. 

I can't really comment on the Chinese, from the dictionary it seems that 能 isn't a verb, but a prefix.  Chinese grammar is very different from English.