Couldn't is the opposite of could.
The opposite could be trusting, or secure, or unconcerned, unworried.
The opposite of thin is thick.For persons, the opposite of thin may be fat, portly, or heavy.For thin meaning tenuous, the opposite could be dense.For thin meaning less than complete, the opposite could be substantial, or complete.Thick
The opposite of abrupt could be gradual, slow, or incremental.Calm, kind, nice...
The opposite could be distrust, or mistrust, or suspicion.
The opposite of submit (present) would be retract. The opposite of submit (surrender) could be fight, resist, oppose, or contend.
Fiction could be the opposite. Non-factual also could be the opposite.
It could be expectation, or anticipation.The opposite of to surprise could be to bore, or to be predictable.
The opposite of bright (color, shine) could be dark The opposite of bright (light) could be dim, dull, or low. The opposite of bright (day, disposition) could be gloomy. The opposite of bright (idiom - clever) could be dull, or unintelligent.
The opposite of bright (color, shine) could be dark The opposite of bright (light) could be dim, dull, or low. The opposite of bright (day, disposition) could be gloomy. The opposite of bright (idiom - clever) could be dull, or unintelligent.
The opposite of a purpose for a tool could be its form. The opposite of the purpose for an action could its plan. The opposite of (having) a purpose could be purposelessness or randomness. * For "on purpose" the opposite is accidentally, inadvertently, unconsciously.
The opposite of "by" can depend on the context in which it is used. In terms of direction or movement, the opposite of "by" could be "towards" or "into." In terms of ownership or responsibility, the opposite of "by" could be "without" or "not by."
The opposite of accused is not accused, which could be cleared or uninvolved. The opposite status could also be exonerated.
The opposite of emotional calm could be:excitedenthuseddisturbedupsetanxiousscaredmadexcitedhystericalstressedjitteryThe opposite of calm (wind, sea) could be:windystormy
The opposite in terms of human physiology could be "mind."The opposite in metaphysical term could be "soul."The opposite of a body blow (boxing) is a punch to the face.The opposite in terms of human physiology could be "mind."
It could be:to do nothing.Or, it could be to do the opposite thing.
The opposite could be earn.The opposite, not to spend, is to save.
The opposite of preserve could be destroy or consume. The opposite of preserving food could be consuming and/or wasting it.