Dear Neha,
Your question has a deep meaning and an online answer may not be able to do justice to your query. But let me put some thoughts.
A person's nature is what we can also call the 'personality'. Personality is a pattern of a lot of factors. It involves the unique way a person thinking about something, responds to problems, reacts to events, takes decisions, thinks about self and others, etc. This pattern can differ from person to person, and we see people with different personalities (natures).
Attitude is mostly a subjective thing. The way you think about an event may be perceived by a person as a positive attitude, while a third person might perceive it as a negative attitude. As far as an individual is concerned, the attitude can be negative or positive based on what that individual’s goals are. So, what is positive for you may be criticized by others as a negative attitude! And attitude is just one aspect of nature (personality).
Now coming to your question 'how to know the actual nature'. A practical way to do this is start with exploring the event or situation which has prompted you to ask this question. A pen and a paper will be quite useful.
1) Explore your 'self-talk' about that particular event/situation. Self talk is the thoughts that come to your mind about that event. Try to see if you derive meaning from what happens to you (the event). If yes, see if those meanings are helping you maintain your peace of mind, or are creating disturbing feelings.
2) Try also to see if you have certain hard wired beliefs about the event. These beliefs could be irrational (self-defeating) and creating the negative emotional consequences for you.
Thus, you are looking for the way you think about an event. And for you, the attitude will be positive, if those thoughts lead you to your goals. We call them rational thoughts or rational beliefs, in psychology terms.
You often see people criticizing others saying "you have a negative attitude", whereas the person might be having totally rational thoughts that help him/her, but may not be rational from the point of view of others.
For a better understanding, please read this short article. You might even get some more insights about any problems you might be facing today.
http://www.medhelp.org/user_journals/show/211513/Understanding-Irrational-Beliefs
If you want to know if you are clinically depressed, you will have to
consult a Psychiatrist personally and get your symptoms evaluated. There are no alternatives to a face to face consultation with the doctor. The test mentioned above by Dr. Pandya can give you an indication how much depressed you are. This test can also help you monitor the level of your
depression over a period of time. You can take the test once a month and see if your score declines.
Some of the common symptoms a person has in depression are sadness of mood,
fatigue, sleep disturbance, appetite disturbance, loss of interest in the surrounding, suicidal thoughts or thoughts of harming self, etc. Please do not diagnose it yourself.
Hope this helps you a bit. Please let us know if you need more information or need to discuss more.
Take care.
Abhijeet Deshmukh, MD