The two n's

In Malayalam there are two pronunciations for the letter ന. One is the 'dental', denoted by n̪, similar to the n sound in 'month'. The other is the 'alveolar' denoted by n, similar to the sound in 'nice'. 

In Paniniyam introduction, AR uses different letters to indicate these sounds. 

The following words show that these are indeed different phonemes (since they change the meaning when ന is pronounced differently)

word	meaning when pronounced as dental	meaning when pronounced as alveolar
എന്നാൽ	however	by me
നിന്നാൽ	if (somebody) stands	by you
തന്നാൽ	if (somebody) gives	by self
ഇന്നത്	today, that (ഇന്ന്  + അത് )	this (particular) one

Do you know other words that demonstrate this difference? 

Sweet south

In the US, South and Sweet has a wonderful connection. If you have had Sweet Tea from the south you'd know what I am talking about.

It seems this is not just limited to the English world.

In Malayalam too, the root തെൻ has both meanings - south and sweet.

The word for honey or nectar is തേൻ, which is the intentisified version of (തെൻ). Similar to തിൻ  >  തീൻ.

തെൻ is also the root of the ubiquitous തെങ്ങ്. Its fruit is തേങ്ങ, which comes from തെങ്ങിൻ കായ്, similar to മാവിൻ കായ് becoming മാങ്ങ. Interstingly, തേങ്ങ can also be derived as തേൻ+കായ് , meaning sweet fruit.

തെന്നൽ is breeze. Looking at its etymology, it may have originally denoted 'southern wind'.

A new word I learned recently is തെണ്ടിര < തെൻ + തിര  meaning 'south sea'. This is an example of adesha sandhi. (Similar to വിണ്ടലം < വിൺ + തലം)

The standard malayalam word for south is തെക്ക്. ശബ്ദതാരാവലി lists both തെൻ and ദക്ഷിണ as possible etymologies. To me, the tatbhavam from ദക്ഷിണ sounds more possible.

In any case, south and sweet are linked in Malayalam too. 

Room and walls

It is interesting how the same etymology in two languages gave rise to related concepts.

In Malayalam, the word for room is മുറി. It comes from the root മുറിയുക, to split. After all, a room is a split or portion of the house. Compare, തേങ്ങാമുറി - the half of a coconut.

The word for wall is ഭിത്തി. This is a തത്സമം from Sanskrit. It comes from the root भित which means to 'split'.

Thus the etymology is identical in both words. One came to mean room and the other came to mean wall. In other words, one focused attention on 'that which splits' and the other on 'that which is split into'.

For comparison, the English word room comes from PIE root *reuƏ which means to open up. Wall comes from a root that originally meant post or pillar - presumably, the original wall was made by a row of posts.