deriv LSK ETT STT aSTA ALPH OLDHOMEPAGE NEWHOMEPAGE
If you are the sort of beginner that cannot yet tell that AsId rAjA nalo nAma आसीद्राजा नलो नाम is AsIt आसीत् + rAjA राजा + nalas नलस् + nAma नाम, then studying the /sandhi rules, (4like the rule hazica that changes nalas नलस् + nAma नाम into nalo nAma नलो नाम) is mostly a waste of time.
When you learn Sanskrit, you don't need to APPLY the rules, you need to get used to IGNORE them. This is so confusing for beginners that sankrita bharati just gave up on teaching that in their conversation clases, and they get their students to talk with bad sandhi in order to make things easier to them.
Yet I don't make this website for people who want to chat sucky sanskrit, but for people who want to do half-serious work like, say, reading the rAmAyaNa रामायण. So you don't get to be cuddled, sorry.
What you need to learn is not rules, but splitting. You read somewhere or hear from someone AsId rAjA nalo nAma आसीद्राजा नलो नाम, and you guess that the o ओ might be as अस्, because most words that appear to end in o ओ are actually as अस् enders that changed as अस् into o ओ before a haz letter or a short a अ.
A quite efficient, but hard, way to learn that is the book the story of nala.
Also, the inria reader sometimes helps to split things. Type nalonAma into it and see what happens.
See sandhi tables.