The English language has an abundance of words to express dependence. Some synonymous phrases to "were dependent upon" include "relied on," "had to have," "were contingent on," "rested on," "depended on," "were conditional upon," "were hinged on," "were subject to," and "could not function without." Each of these phrases carries their own strengths and limitations in conveying the level and type of dependence. Choosing the most suitable synonym is dependent on the context of the sentence and the desired emphasis of the message. It is important to remember to select a term that accurately reflects the intended meaning to avoid any confusion for the readers.