I think teach–learn is a causative–anticausative pair.
teach = cause someone to learn (or alternatively, cause someone to know)
I think it's common in languages to have teach be a causative-derivation of either a verb meaning learn or one meaning know. Alternatively, teach may be the primary form and learn an anticausative-derivation from this. The reflexive in Polish mentioned above essentially works this way, I think. Swedish does the same, having lära for ‘teach’ and lära sig for ‘learn’. This is typical of European languages, where the causative tends to be the primary form and the anticausative the derived form.
Proto-Germanic seems to have had a stative *lizaną meaning ‘to know’ from which was derived an inchoative *liznaną ‘to learn (to enter into the state of knowing)’. The latter gave English learn. There was also a causative *laizijaną meaning ‘to teach (to cause someone to know)’, though this is derived from the stative *lizaną and not the inchoative *liznaną. The causative gave German lehren.
Send could be thought of as a causative form of receive, at least some uses of the verb send where there is a recipient. Send someone something = cause someone to receive something.
Come–Go is another type of verb pair, though, which has already been mentioned.
Edit:
See for example here:
http://www.eva.mpg.de/lingua/conference ... atives.pdfAs mentioned in the article, it is perhaps best to talk of the verb pair as plain verbs vs causal verbs. The otherwise ambiguous terms anticausative and causative can be reserved for overtly coded plain and causal.