If your computer does not have the necessary files to support complex Devanagari combinations, then the combinations here may not look especially noteworthy.
These combinations are produced from two consonants. These consonants combine so much that it's impossible to recognize them in the result. However, both of these combinations are common enough that you should know them.
Letter with a vertical line on the right + Letter
When these letters come first, they lose their line and attach to the consonant that follows them.
Letter + र
The र is added to the letter with a little mark on the bottom of it. For letters with a "hoop" (ट ठ ढ द), this mark looks like the caret sign (^).
dya, dma, hya, hma
śra, śva, śca, śla
In these combinations, श is distorted to make room for the letter that follows it.
dgha, ddha, dbha
In these combinations, the aspirated letter (घ ध भ) attaches to the bottom of द. Due to sandhi, combinations like ट्भ never occur.
Other Odd Combinations