Hi Christophe,

Only "to bringing on" is correct in this case. "To bring on" is incorrect. You might be thinking that, because you are saying/writing "to bring," it's an infinitive, which is often interchangeable with a gerund (since both can be used as nouns). But in this case, "to" is already a preposition in the sentence ("the best approach to"), so it doesn't form part of an infinitive. Your choices would be either "approach to bringing" (gerund) or "approach to to bring" (infinitive). And of course, the second choice just looks and sounds bad.

Ugh...I just wrote all that and thought my explanation made perfect sense, but then I realized one <em>can</em> say "the best way to bring," and one <em>cannot</em> say "the best way to bringing." Apparently, this is one of those distinctions that can only be learned word by word. (Kind of like which verbs take "à" and which verbs take "de" before an infinitive in French.) So my first paragraph sounds logical but is actually deceptive.

The best approach to learning... Or, the best approach for learning...

The best way to learn... (Or maybe even, the best way for learning... But that's a bit awkward.)

The best means of learning... Or, the best means for learning...

The best strategy for learning...

When in doubt, I suggest "for+gerund." It seems the safest option. But if you're willing to make mistakes, you'll learn from each instance. We all know English makes very little sense. (Anglophones can be reluctant to correct people; at least, they are here in the US. So you may have to ask very clearly that people correct you in conversation if something doesn't sound right.)