I am having a trouble with correct usage of the definitive article and capitalization in the following sentence:

Both Earth's and human health are the topics I love.

Is this sentence correct ↑ or should I use one of these? ↓

Both the Earth's and the human health are the topics I love.

Both the Earth's and human health are the topics I love.

2 Answers 2


You can have situations where the entire planet is almost completely rock/ice/water (such as the Earth), or situations where a large amount of gas is subsequently attracted to the rock/ice core (such as Jupiter, Saturn, etc.). [OK]

A text from an authority on planets

Why does NASA study Earth? [OK]

A test from another authority authority on planets:

Both are used. And please note: in either case, if you are saying the rotation of the Earth, even if your text is not using the determiner "the", you would have to use it for the "genitive".

  • Both the Earth's and human health are the topics I love. [OK in speech]

  • Both Earth's and human health are topics I love. [Ok in speech]

If one is writing a text, perhaps the clearest way might be:

Both human health and (the) Earth's health are topics I love.


Both (the) Earth's health and human health are topics I love.


I put the "the" in parenthesis, because both are grammatical. It is the speaker's choice here.

For me, the sentence given in the question does not lend itself to one noun possessed by Earth and humans. That is because we would not write in a formal text:

- John's and Mary's health.

For clarity's sake, one would write:

- John's health and Mary's health.

Whereas you could say: John and Mary's car, where car belongs to both of them. With health, they each have or don't have health, as separate entities.

Please note: this is a stylistic suggestion based on the fact that the word health belongs to entities in a separate manner. So, I suggest repeating the noun health, rather than using a single possessive. Some languages do not "like" word repetition, but in English, that is not an issue.

  • With a non-count noun like 'health', possessed by plural entities, you may use a possessive on each noun, e.g. John's and Mary's health, Peter's and Harry's money. When multiple nouns “possess” the same entity, only the second takes an apostrophe: my aunt and uncle’s house; when the nouns possess different entities, both possessives take an apostrophe: my aunt’s and uncle’s specific talents. (Chicago Manual of Style) writingtips.wordpress.com/2008/06/27/possessive-with-two-nouns Apr 29, 2018 at 19:13
  • There is no non-count noun possessed by plural entities. There is a non-count noun that goes with two separate individuals. Perhaps you should post that paragraph in your own answer? I was clear that I was giving an answer for spoken/written style. The Chicago Manual of Style is only for writing, not speech.
    – Lambie
    Apr 29, 2018 at 21:25

Your initial sentence is correct, as long as those are the only two topics that you love:

Both Earth's and human health are the topics I love.

If they are two topics that you love, but there are others, then omit 'the' before 'topics'.

When the noun earth refers to our planet, it is capitalised only when it is a proper noun (meaning it acts like a name and is not preceded by the — e.g. everything on Earth).

The word is not capitalised when it is a common noun (meaning it does not act like a name and is preceded by the — e.g., everything on the earth), so you could have this:

Both the earth's and human health are [the] topics I love.

In either case you would not use a definite article ('the') before 'human health', since the phrase denotes a mass (non-countable noun).

  • When referring to the planet, it's either Earth (no definite article, capitalised), or the earth (definite article, not capitalised) Apr 29, 2018 at 13:52
  • @MichaelHarvey I think if you are responding to Lambie you have to tag them to send a notification to that user. Otherwise, they won't see your comment unless they come back to this post and check.
    – Eddie Kal
    Apr 29, 2018 at 15:04
  • 1
    I find all existing variations of this to be very awkward. Although I agree with yours (technically), I would rephrase the sentence (and not just the specific word): Planetary and human health are both topics I love. (Or, if Earth must be used in order to avoid confusion with other planets: Earth's health and human health are both topics I love.) But, really, I'd throw out the whole construction and start again . . . ;) I can't think of many people who would naturally say "are [the] topics I love." Apr 29, 2018 at 22:21
  • @JasonBassford I said the same thing. To repeat health is best if one insists on (the) Earth's health. Also, I would start the sentence with: Topics I love are A and B.
    – Lambie
    Apr 29, 2018 at 23:33

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