I could be talking fine&then i sound nasally& people ask if have a cold. i could start a conversation&people think i have a cold/nasal when i'm ok. ?

The nose: The nose is a very reactive anatomic structure and can have internal swelling in response to many different things ranging from airborne allergens, to scents, to eating foods, to changes in Adrenalin and blood flow, to colds, to smoke, etc... None of these responses is a sign of anything wrong per se. If you have chronic obstruction to airflow or sinusitis, that warrants an eval for polyps, etc..

Complicated.: Depends on what you mean by "nasally". Hyponasal means you sound like your nose is blocked and you have a cold. This is normal periodically. Hypernasal means too much air coming through the nose, like some cleft palate patients have. If this is what is happening to an adult, it could be an early sign of something more serious. You should then see your ENT doctor.