Please capitalize where necessary: he has to stand aside from himself and observe the chief events of his life with philosophic detachment.
A: He has to stand aside from himself and observe the chief events of his life with philosophic detachment.

Q: he worked at harvard university from 1945 to 1972, first as an associate professor but being promoted to full professor in 1947.

A: He worked at Harvard University from 1945 to 1972, first as an Associate Professor but being promoted to full Professor in 1947.

Q: export messages retrieved through search to standard formats for additional review.
A: Export messages retrieved through search to standard formats for additional review.

Problem: for about 26 million years ago appeared elephant, deer, and the dog animal predecessors.
Can you repeat this sentence, but capitalize it?
Answer: For about 26 million years ago appeared elephant, deer, and the dog animal predecessors.

Text: if so, you can make yourself happier right now. in the next thirty minutes, check off as many of the following items as possible. each one will lift your mood, as will the mere fact that you've tackled and achieved some concrete goals; by doing so, you boost your feelings of self-efficacy, which can boost happiness.

Correct capitalization: If so, you can make yourself happier right now. In the next thirty minutes, check off as many of the following items as possible. Each one will lift your mood, as will the mere fact that you've tackled and achieved some concrete goals; by doing so, you boost your feelings of self-efficacy, which can boost happiness.

Text: it supports preview - users can choose to preview the input files before converting7.

Correct capitalization:
It supports preview - Users can choose to preview the input files before converting7.