I am in doubt about my sentence. I am trying to describe around 73% accuracy that can be obtained using a mentioned method. So, I have written:

The study of Sen et al (2012) has shown that a tree canopy can be detected with about 73% overall accuracy.

Can I use with about together, one after the other?

  • Why do you think that you can't? Nov 5, 2012 at 11:02
  • 14
    Let me step out from behind my tree and tell you the story of a little boy who asked his father, "Daddy, what did you bring that book that I don't want to be read to out of about Down Under up for?"
    – RegDwigнt
    Nov 5, 2012 at 11:15
  • @ RegDwighт: thanks for the clarification & examples.
    – gnp
    Nov 5, 2012 at 11:32
  • 3
    @RegDwighт Why are you hiding behind a tree? ;)
    – apaderno
    Nov 5, 2012 at 11:33

2 Answers 2


There's nothing wrong with what you've written. In that context, about is not a preposition, but an adverb, meaning approximately.

There are other usages where consecutive prepositions are acceptable, too. For example, sometimes prepositions can build on each other, as in:

  • He went up over the hill.

or when one preposition is used as part of an idiom or phrasal verb:

  • What did you have to bring that up for?

  • The oven will cool down after we shut it off.


You can certainly write with about 73% accuracy without violating any grammar rules. However, the sentence is awkward and needs rephrasing.

Some suggestions for writing better sentences in this kind of academic paper.

(A) Don't cite author names unless they and their work are extremely well known and using their names adds background value to your sentence. The bibliography or reference list is where author names belong.
(B) If you're discussing many authors and need to sort out who said what, then, of course, you must use author names, no matter how well known or unknown they are. And if you want to point out that your results and findings disagree with those in another study, then you need to mention the authors' names.
(C) Instead of saying "The study of Sen et al (2012) has shown...", you can eliminate a bit of verbosity by saying only Sen et al (2012) {have shown / showed / reported [CHOOSE ONE]}....
(D) I don't understand that tree canopy can be detected with about 73% overall accuracy. The definite article is missing between that and tree. Does this refer to leaf area index (LAI, leaf area per unit ground area)? If so, then the sentence should read something like this:
(E) Sen et al (2012) have shown that the leaf area index (LAI) of the tree canopy can be estimated with about 73% overall accuracy.
(F) The leaf area index (LAI) of the tree canopy can be estimated with about 73% overall accuracy (Sen et al, 2012) is shorter and also possible, but it might not be appropriate for the style of the paragraph.
(G) Eliminate all unnecessary words! I cut five words from your original sentence and added six (leaf area index (LAI) of the) that do work because they provide additional information. If those six extra words are unnecessary, then the final sentence is 25% shorter than the original. Be kind to your readers and delete useless verbiage.

  • 3
    Your recommendation a is actually not an option in many required academic styles.
    – TRiG
    Nov 5, 2012 at 12:11
  • @Bill Franke: thanks for commenting on academic styles
    – gnp
    Nov 5, 2012 at 12:34
  • @TRIG: What? You mean that there are actually style books other than the APA Style Manual, that prescribe Beschissenenglisch? APA requires author names in-line in the text when citing references, but it doesn't require author names outside the parentheses. I think (E) & (F) take care of that style problem. Naturally, if the style manual one is using requires author names, you use them, & sometimes the (E) style is better than the (F) style--I use both if I must. But whenever possible, avoid the verbosities of The study of Smith et al & Smith et al's study: Use Smith et al (2012).
    – user21497
    Nov 5, 2012 at 12:56

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