Simple into Double or Compound Sentences

Simple into double or compound sentences:
1. Double sentence के finite verb को participle (verb+ing) में बदल दिया जाता है, या
2. आवश्यकतानुसार उस जगह to, for, after, by, unless, owing to, in spite of आदि का प्रयोग किया जाता है।
For example:
Double (Compound)-
(a) He came and took away my pen.
Simple-
(a) Coming here he took away pen.