Those are definitely tricky words to define, however I will try my best ;-) (there's one example already!)
Whatsoever- Most often used as an adjective meaning "at all." An example would be, "What you are doing does not help me whatsoever."
However - There are 4 main ways this word can be used, as an adverb or a conjunction
1. nevertheless; yet; on the other hand: example: "We haven't won yet, however, we will keep trying."
2. to any extent or degree; no matter how: "However much you spend, I will reimburse you."
3. in any manner: "We will allow you to travel however you please."
4. in whatever way, manner, or state: "Color this drawing however you would like."
Though / Although - These words can usually be used in the same way, meaning "despite the fact that..."
"Although he ran as fast as he could, the car was still faster."
"Hopefully my examples make sense to you, even though I am not a very good english teacher." =)
Somehow - "in any way", or "by any method"
"'I will get there somehow." or "Somehow I have to do this math problem without a calculator."
Hopefully this helps a little.. if you want more help with them or more examples feel free to send me a message. =]
p.s. see if you can understand this.. haha
Although at first I had no idea how to describe these words whatsoever, somehow I found a way. However, I am not sure if what I said makes any sense to you, though I would be happy if it does. =]