"If however" is a phrase that introduces a contrasting idea or condition to a previous statement. Some synonyms for this phrase include "yet," "nevertheless," "although," "but," "still," and "conversely." Each of these words can be used to express a different level of contrast, from a soft contrast to a more firm and direct contradiction. For example, using "although" suggests a mild contrast, whereas "conversely" presents a more direct contradiction. Choosing the correct synonym for "if however" depends on the desired tone and emphasis of the sentence, but all can effectively express a shift in thought or condition.