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It can be one word and two words it just depends on how you are using it. As a noun it is one word. If "flow" acts as a verb (for example, "the work flows well"), use two words.
work site Two words
The term "workflow" is typically written as one word.
"Work time" is written as two words.
one word
"Homework" is typically written as one word.
Work site, two words.
It's one word.One word as an adjective; two words as a noun
"Workstation" is typically written as one word.
It is the "Deuce," which means the two (2) days off you get from work after you finish each week. :)
"Test work" is typically written as two separate words.
The word workflow can be spelt as a single word.