The way to write an acrostic poem is first to learn about your subject. That means you have to do your homework and learn all about osmosis.Next, write the word downwards on the page, with one letter on each line.OSMOSISFinally, think of some facts about osmosis and make them fit the letters on each line. In other words, think of a way to say your facts with the first word starting with O ... you could write "Osmosis is ____" and define it as your first line. Then just go down the list and think of words starting with each of the other letters so you're giving facts about the subject as you write.