I was always taught to capitalize the first letter of the first word in a sentence, and also the first letter of proper nouns. In the last few years it's been common for certain firms to name their brands something that is always spelled with a small first letter and a capital second letter. It is almost as if they demand the rules of usage are changed. What do you do about this? Where is the inquisition when you need it? Should you start a sentence with "IPhone"? Should you use "iphone" in the middle of a sentence?

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    It's called CamelCase: en.wikipedia.org/wiki/CamelCase
    – paradroid
    Commented Sep 10, 2011 at 21:57
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    I suppose it's up to you which rule you give priority, but I'd have thought the right of eBay to say what their own name is outweighs the "right" of pedants to say what constitutes good grammar. Commented Jan 17, 2012 at 5:58
  • There are some interesting points on this here boards.straightdope.com/sdmb/showthread.php?t=505324& Commented Jan 17, 2012 at 6:03
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    Same way you would capitalize McDonald's, whether used as a brand name or a last name.
    – zooone9243
    Commented Sep 28, 2012 at 23:09

3 Answers 3


Brand names

You should never change a brand name. 'iPhone' should always be spelled as 'iPhone,' no matter where in the sentence it is. 'IPhone,' 'iphone,' 'I-phone,' 'i-phone' or 'I phone' are always wrong. 'iPhone' is the only good one:


iPhones are the best selling smartphones.


IPhones are the best selling smartphones.


Iphones are the best selling smartphones.

This is the same for all brand names, but this can also be for other (nick)names invented by people, for example 'rms' which should always be spelled lowercase.


There could be, however, one exception, when the sentence is spelled in all caps, usually for styling purposes:





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    This is true... but to avoid the weirdness of beginning a sentence a lower-case letter I usually avoid putting "iPhone" as the first word in the sentence. Commented Jan 17, 2011 at 15:57
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    @JSBangs: Good idea. It's probably easy to avoid this a lot of the time; for example, the sentence above could be written, "The iPhone is the best-selling smartphone."
    – Andy
    Commented Jan 18, 2011 at 22:06
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    I think this is a case of the general rule that people have the right to decide on their own proper names. Like, if someone is named "Sallee", I don't think others should be saying, Oh, that's mis-spelled, it's supposed to be "Sally", and insist on spelling it that way!
    – Jay
    Commented Jan 17, 2012 at 16:19
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    "You should never change a brand name" - I can see that this is standard usage, but what's the actual justification? I assume there's some published source or style guide somewhere that tries to supply some reason, however post-hoc or arbitrary it might be. (It's not like we honor some companies' desires to slap a ™ next to every single usage of their product name when we write about them in the paper.)
    – Alex P
    Commented Jun 19, 2013 at 16:22
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    I strongly disagree with this. Brand names are not people, and are not entitled to the same courtesy one would extend to a person. When brands choose to tinker with the established rules of grammar and spelling for marketing purposes, it is, to my mind, perfectly legitimate to stick with established rules of spelling and grammar where they improve clarity.
    – Christi
    Commented Aug 2, 2014 at 9:59

Wikipedia suggest that eBay is the correct usage.

eBay announced that starting in March 2008, eBay had added to...

However, I would be interested to see if the same convention applies with abbreviations like mRNA

Again, Wikipedia suggests the same.

mRNA is transcribed from a DNA template, and carries coding information...

However, that's not to say that these are the "official" rules in any capacity.

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    I would definitely give a poor note to a student who wrote MRNA. For whichever grammar reason...
    – nico
    Commented Jan 17, 2012 at 7:21
  • @nico What's a "poor note"?
    – Golden Cuy
    Commented Jul 20, 2012 at 14:45
  • @Andrew Grimm: a low mark when correcting a biology paper/exam etc.
    – nico
    Commented Jul 20, 2012 at 15:57
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    @nico: unlike in French and German, "note" does not mean mark/grade in English.
    – Max
    Commented Apr 29, 2014 at 17:21
  • @Max It does have that meaning in English as well, it's just not a common usage.
    – user91988
    Commented Jan 15, 2019 at 22:05

iPhone is tricky. You have to capitalize it the way Apple does. It is a product therefore has to be labeled the way the brand does. Technically anyway you write it would be correct but if you want to be exact then capitalize the "P" only even it is a the head of a sentence.

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