general astrology

Firstly we have to determine the overall personality by seeing lagna etc.

Then specific to your question – we will check the second house. What I’m saying next is generic and should be modified for predictions due to factors like Rashi, aspect, etc. These effects are expression of the planet’s lower form of energy and will not be applicable if the energy is more refined.

Influence of Mars shows aggressive or angry speech and unparliamentary words.
Influence of Rahu can bring serious abusive words and bad language.
Influence of Sun shows authoritative speech and can bring some touch of ego as well, but Sun is so royal that it normally cannot go against its high status and use abusive language – but if it gets more afflicted then the egoistic speech can fall to a lower level and the person may use abuses sometimes (but this is lesser than above 2 cases and the abuses are generally not very insulting).

If you mean cursing in the sense of giving shraap then:

Influence of Saturn can make the person’s speech very negative, pessimistic, always saying “no” for everything, and can give out curses to people (coming from inferiority, pain, etc etc).
Influence of Jupiter is a blessing and shows “aashirvaad”, but if heavily afflicted then even Jupiter can show a person who gives curses or shraap to people (but this person’s shraap gives temporary difficulty and long term benefit, plus he will generally give the shraap when he thinks it is morally required etc etc).