Yo soy una persona muy competitiva
Yo soy una person muy positiva.
You would say "una persona muy agradable".
To say 'I am a person' in Spanish, you would say 'Soy una persona.'
To say 'He is a person' in Spanish, you would say "El es una persona.'
"Competitive" in Spanish is "competitivo". It is pronounced "koam-peh-tee-TEE-bo". Please see this site for confirmation of the translation: http://www.answers.com/library/Translations
"She was a nice person" in spanish is "ella era una persona amable".
Tá sé an-iomaíoch.
He was very nice (he is a very nice person, always) - Era muy agradable He was very nice (he behaved very pleasantly) - Fue muy agradable
No muy buena is the best way to say "not very good" in Spanish.
Very similar in spanish: Mascota
Say "Muy delicioso!" (Very dilicious.)
deportista