Tasteless. Need more information:do you wear dentures? What medications are you taking? Both of these can lead to altered taste sensations. How long has this been occurring? Are your sinus clear or infected;if you cannot smell you cannot taste. I would refer you to your md and ENT especially if this is a new condition.
Loss of taste. Is commonly due to zinc deficiency. Get a supplement from a health food store + a multivitamin. Check your diet.