Continually vs. continuously
Wrong: The waves continuously beat against the shore.
Right: The waves continually beat against the shore.
Continuously means nonstop, while continually means again and again, at regular or frequent intervals. While the waves may appear to be unceasing, they actually come in intervals.
Followup vs. follow-up vs. follow up
Wrong: We need to followup with him next week.
Right: We need to follow up with him next week.
First, there is no such word as “followup.” It can be written as follow-up (a noun; something that increases the effectiveness of something else), as in: “This will require some follow-up.” Follow-up can also be used as an adjective: “Be sure to write a follow-up story.” In the example above, however, the verb phrase follow up is an action that produces follow-up.There are plenty of words like these. More next time.