Positive
Part of speech: noun
Definition: A thing capable of being affirmed; something real or actual. A favourable point or characteristic. Something having a positive value in physics, such as an electric charge. An adjective or adverb in the positive degree. A positive image; one that displays true colors and shades, as opposed to a negative.
Part of speech: adjective
Definition: Definitively laid down; explicitly stated; clearly expressed, precise, emphatic. Fully assured, confident; certain. Overconfident, dogmatic. Describing the primary sense of an adjective or adverb; not comparative or superlative. Derived from an object by itself; not dependent on changing circumstances or relations; absolute. Wholly what is expressed; colloquially downright, entire, outright. Characterized by the existence or presence of qualities or features, rather than by their absence. Characterized by the presence of features which support a hypothesis. Characterized by affirmation, constructiveness, or influence for the better; favourable. Actual, real, concrete. Of a visual image, true to the original in light, shade and colour values. Having more protons than electrons. Of number, greater than zero. HIV positive.
Example sentence: Live life to the fullest, and focus on the positive.
Certain
Part of speech: determiner
Definition: Having been determined but unspecified. The quality of some particular subject or object which is known by the speaker to have been specifically singled out among similar entities of its class.
Part of speech: adjective
Definition: Sure, positive, not doubting.
Example sentence: What is success? I think it is a mixture of having a flair for the thing that you are doing; knowing that it is not enough, that you have got to have hard work and a certain sense of purpose.