Articulate refers to enunciating clearly and effectively.
At all hours vs At any hour
at all hours—continuously, especially at unusual or irregular times:
Backward vs Retrograde vs Retrogressive vs Regressive
Backward, retrograde, retrogressive, regressive all involve the idea of not moving or going ahead, or forward, or in advance.
Background vs Setting vs Environment vs Milieu vs Mise-en-scène vs Backdrop
Background, setting, environment, milieu, mise-en-scène, backdrop are comparable when they refer to persons and their actions as found in real life or as represented in art and denote the place, time, circumstances, and conditions in which those persons live or carry on their activities.
At all events vs In any event
Note: The expression is not equivalent in meaning to the phrase in either event—no matter which of two possibilities happens:
Arthroscopic vs Orthoscopic
Arthroscopic is the correct word.
Awry vs Askew vs Askance
Awry, askew, askance mean deviating from a straight line or direction.
Artful vs Arty
Artful means skillful or clever.
At a word vs In a word
at a word—following the word of command:
Awkward vs Clumsy vs Maladroit vs Inept vs Gauche
Awkward, clumsy, maladroit, inept, gauche mean not adapted by constitution or character to act, operate, or achieve the intended or desired ends with ease, fitness, or grace.
At a white heat vs In a dead heat
at a white heat—in a state of intense or extreme emotion:
Arrhythmic vs Eurhythmic
Arrhythmic refers to lacking rhythm or the regularity of rhythm.