Corrections in red.  Stylistic suggestions and comments in blue.

One Sentence in Different Tenses      Capitalize the first word, last word, and all "important" words in a title.  Do not capitalize prepositions or articles, unless they are the first or last word.

simple past:
I studied this book last month.
simple present:
I study this book.
simple future:
I will study this book.
present continuous: 
I'm studying this book for an/the exam.   Use "an" if the reader does not know which exam you're writing about.  Use "the" if the reader does know.
past continuous: 
I was studying this book last term.