Dear Terri, 

There are general signs that are common to all vocations, and then specific signs that tell if you are a possible candidate for a particular group or order.  

The general signs have to do with physical health, psychological health, maturity proper to your age, intellectual ability, spiritual health and a spiritual motive.  

The specific signs are the general ones as they apply to a particular group with its own standards and requirements, and any additional requirements they might have that relate to their specific charism and apostolic work.  

Just to explain very briefly the general signs: 

- physical health means normal health for a young person, with no physical condition that would keep you from fulfilling habitually the normal duties and responsibilities involved in the particular vocation you are considering.  

- psychological health means the same, but applied to your psychology: freedom from illness, addictions, psychosis or neurosis, obsessions, etc... Ability to weather the normal stress involved in the vocation,  

- maturity proper to your age is connected to a certain degree with psychological health: to have the ability to discern, a functioning conscience and will, independence from peer pressure, emotional stability, etc. Obviously you would expect more in this regard from a mid-twenty-year-old than a seventeen year old, so that's why we say 'proper to your age' 

- intellectual ability. Since in most vocations you have to take college studies you need to have the necessary ability, but that is not true of every vocation so you should ask the group you are interested in.  

- spiritual health. You usually need to have acquired a certain stability in your spiritual life, though you might still have your struggles. This means that you are not too recent a convert, not given to strange devotions, that you give God his place, have an active faith in the Church as Christ founded it, etc... 

- spiritual motive: this means that in looking into the vocation you are motivated by something more than human convenience or ambition - a desire to save souls, to use your life in the most pleasing way to God, to bring God's mercy to others, more concern for what you are called to be than what you are called to do.  

Terri, I hope this helps clear things up somewhat for you. It is very brief, I know, but you will probably be able to connect it with your own experience. 

Particular groups will have also their own requirements as regards age, studies completed before joining, etc.