Many writers make dubious choices of verbs to cite prior work. Students, and even fulltime academics, pick up and use words without knowing their meaning. Perhaps this is because words such as posit and opine sound nicely intellectual. Whatever the motive, many a word is a poor choice, if not an outright error. Here are six prime cases to look out for.

1. Posit

Misconstrued meaning: Posit does not mean declare or state a fact.
Actual meaning: Posit means to suggest something is true, while implying that we do not know for sure that it is. Further work needs to be done to verify the claim.
Since posit is synonymous with postulate, the same principle applies to postulate. However, we have found posit is used often whereas postulate rarely is.

2. Opine

Misconstrued meaning: Opine does not mean to state or to report a finding or theory or to reach a conclusion.
Actual meaning: To opine is to express an opinion.
Even if used correctly, opine is a poor choice of word. It is rarely, if ever, used in everyday speech and rarely used by writers whose intention is to be clear rather than to show off.

3. Assert

Misconstrued meaning: The error with assert is more subtle. Typically, the word is correctly understood to mean make a declaration forcefully, to state emphatically something as fact. It is the connotation that writers get wrong.
Actual meaning: To assert is to declare something as truthful but with the implication that others may see otherwise. An assertion is a declaration in the face of contrary evidence or a contrary opinion. That opinion can be explicit or implied.
Consider the case in which Murphy conducts a laboratory experiment measuring ball speeds, reports his results, and these are cited by another author. If the author writes:

🗴  Murphy asserted that the ball speed was measured at 80 km/h

you would have to wonder why Murphy needed to make such an assertion, as if his finding was in doubt, rather than simply reporting the measurement. Why not simply cite the finding by saying:

✓  Murphy measured the ball speed at 80 km/h.

Or to subtly distance oneself from the finding:

✓  Murphy recorded the ball speed as 80 km/h.

It would be different if Murphy was aware of doubts about his measurements, in which case the following would make sense:

✓  Despite uncertainty about the accuracy of the measuring instrument, Murphy asserted that the ball speed was 80 km/h.

4. Emphasise

Misconstrued meaning: Emphasise does not mean to assert or to make a statement that it is important, relevant, or useful.
Actual meaning: Writers appear to overlook a quality of emphasis that sets it apart from mere statement, namely, that to emphasise is to place the focus or importance on one thing to the exclusion of others. If such an exclusion is not present, you should not be using this word.

5. Reiterate

Misconstrued meaning: Reiterate does not mean to emphasise or to be adamant about an opinion, theory or fact.
Actual meaning: To reiterate is to state again, one or more times. If your cited source made the point only once, do not use reiterate. Even two statements probably do not warrant reiterate. If repetition does not apply, do not use this word.

6. Testify

Misconstrued meaning: Testify does not mean make an observation.
Actual meaning: To testify is to give evidence in a court of law. Its meaning can extend beyond the courts, but the implication remains that to testify is to give an eyewitness account of an event observed.
Why not use it then for observed empirical findings? Technically you could (the literal meaning is correct) but it does not fit the common use of the language. A native English speaker would find the following most odd:

🗴  With the cathode ray tube experiment, Thomson testified that, when the dipoles were applied, the ray was deflected towards the positive pole.

One would only expect this if the experiment was subject to a court case or a formal enquiry. Therefore, rather write:

✓  With the cathode ray tube experiment, Thomson observed that, when the dipoles were applied, the ray was deflected towards the positive pole.