According to the spelling of the Spanish language, these expressions are used with the meaning of ‘immediately thereafter’ or ‘in a very short time’ and, although the spelling in two words is considered valid (right away)it is preferable to write it in a single word (immediately), since, according to the pan-Hispanic Dictionary of doubts, it is the most widely used.
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Thus, the following phrases found in the media are valid: «Although it opened at a difficult time, its opening was immediately noticed in the streets of the city» and «It immediately distinguished itself for acting decisively, boldly and quickly in the face of the crises”.
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The entrance Immediately, in a word, more advisable than in two was first published on newspaper TODAY.