The word “only” is commonly used in scientific writing in descriptions of results. Depending where it appears in a sentence, the meaning will change. Make sure you place “only” immediately before the word or phrase you want it to modify.
Compare these two sentences:
- The results only showed that the knockout mice lacking Parkin genes exhibited neurochemical abnormalities.
- The results showed only that the knockout mice lacking Parkin genes exhibited neurochemical abnormalities.
- The results showed that only the knockout mice lacking Parkin genes exhibited neurochemical abnormalities.
The first two versions suggest that the results gave information about the knockout mice, but the results did not show anything else. The results did not give any information about the other mice. In these versions “only” means “merely” or “nothing more besides.” It modifies the verb “showed.”
The third version is the more likely version. It implies that among all of the mice studied, the knockout mice that lacked Parkin genes—and none of the other mice—exhibited neurochemical abnormalities. In this version, “only” means “solely” or “exclusively.” It modifies the noun phrase “the knockout mice lacking Parkin genes.”
The two sentences below show these differences in a more humorous manner.
- Dr. Garcia only eats pancakes on weekends.
- Dr. Garcia eats pancakes only on weekends.
The first sentence suggests that Dr. Garcia does nothing each weekend except eat pancakes. She doesn’t eat anything else and she doesn’t do anything else. She spends her whole weekend eating pancakes. The second version tells us that the only time Dr. Garcia eats pancakes is on weekends. She doesn’t eat pancakes on weekdays.
The bottom line: To ensure accuracy, choose carefully where to put the word “only” in your sentence.