This selection comes out of SHIIJIE HANYU JIAOXUE, “当作”and “看作”，Wang Hongqi.

The meaning of “当作” could be taken as “changing A into B in behaviors”, while the meaning of “看作” could be taken as “regarding A as B on the mind”. “当作”contains “看作”. Besides, it has its own meaning. Their difference in sentence and semantic aspect are settled by the difference and similarity of them. So does the exchanging condition.

Foreign students meet with some intricate Chinese words inevitably, when learn Mandarin e.g. “当作”and “看作”. They are very close in meaning so that they can exchange without changing the meaning of sentence obviously.

E.g. 小伙伴们一直把我当作/看作他们的老师。
诺亚把拉宾看作/当作第二个父亲。
Since they are close in meaning, they can be used alternately in works to avoid repetition.
我不把杂文看作纯文学，而是当作普及性读物。
你可以把它当成一句警语，也不妨碍将它看作一则预言。

Because of their closing meaning, they are regarded as synonym in some reference books and used to make comments each other. E.g. the third explanation of “当” in The Dictionary of Modern Chinese is “作为，当做”. This explanation contains “看作” which is interpreted as “认为，作为，看成”. The entry “看” which concludes “看做” is paraphrased as “当做”. There is anther example. “当” is interpreted as “见‘当做’” in the XIANDAI HANYU BABAI CI compiled by Lu Shuxiang mainly. However , it interprets “当做（当）” like “作为，看成”. So it treat “当做”and”看成” as synonym as well.
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