自学印地语打字整理文本是在大脑里面复制外语

The reph comes at the very end of the syllable in words like शर्मा   sharma (where it's above the vowel sign T) and like विद्यार्थी vidyarthi (where it's above the vowel sign T).
When र  is the second character of a compound it turns into a little slanting line, tucked into a convenient nook of the first character:

ग +र =ग्र सिग्रेट sigret cigarette
द+र=द्र द्रोही  drohi hostile
प+र=प्र प्रदेश prades state, region
See what happens when no nook is available:
ट+र=ट्र ट्रेन t.ren train
ड+र =द्र ड्रामा d.rama drama

some conjuncts stack vertically:
ट+ट=द्द छुद्दी  chutti （chu+ddi） holiday
ट+ठ=टठ चिटठी chitthi letter
क+त=क्त भक्ति  bhakti devotion
क + श=क्ष  रक्षा protection

Most conjuncts are easy to read, but there are some in which the
conjunct has limited resemblance to its component parts, and these
have to be learnt as new characters in their own right:
क+त=क्त भक्ति  bhakti devotion
क + ष=क्ष    रक्षा   rakashaa protection

त+त =त्   कुत्ता kutta dog
त+र=त्र   मित्र mitr friend
द+भ=द्भ  अद्भुत adbhut wondrous
ह्+म =ह्म ब्रह्मा Brahma Brahma (a deity)

The rare character जन  jna is a conjunct of ज  with ना na, a nasal consonant (like the first 'n' in 'onion') that is not shown in our table because it never occurs alone; jna is usually pronounced 'gy'.When pronouncing doubled consonants, just 'hold' the sound momentarily, as in distinguishing 'night train' from 'night rain'.Practise with कुत्ता  kutta 'dog', बिल्ली  billi 'cat', बच्च bacca 'child'.

Nasals
A nasalized vowel is produced by diverting part of the breath through
the nose: speak while pinching your nose to hear what it sounds like!
Nasalization is marked with a sign called candrabindu, 'moon-dot':

हाँ   han yes
कहाँ kahan where?
यहाँ yahan here
If there's a vowel sign above the top line, there won't be room for the moon (candra) , so the dot (bindu) is used alone:
नहीं nahin no
कहीं kain somewhere
यहीं yahin right here

Nasalizing a vowel can change.the meaning, as with है  hai 'is' and है hai 'are'. Similarly, while यहीं  yahin means 'right here', यही  yahi means 'this one, this very one' - a completely different word!

Our little dot has a second function also (here with a new name -'anusviir');it can be used to indicate an 'n' or 'm' when such a letter is the first element of a conjunct:
अंडा=अणडा anda egg
हिंदी =हिन्दी hindi Hindi
लंबा=लम्बा lamba long, tall