Nouns are very, very common, so you will need to use a lot of them when you play details! Nouns are used as subjects (they "do" whatever the verb describes) and objects (the action of the verb gets done to them). Example:

Clowns eat pineapples.

"Clowns" is the subject of the sentence (what "does" the eating), and "pineapple" is the object (it shows what was eaten).

Nouns are also used with prepositions —we say the noun is the "object" of the prepositional phrase.

Clowns eat pineapples in Paris.

Often, singular nouns require an article (a, an, or the) to make it clear exactly what noun the speaker is talking about. There is a big difference between A dog barked and The dog barked.

Articles are part of a group of adjectives called "determiners". Other determiners include my, those, some, et cetera. To use most determiners, because they're adjectives, you need to use an adjective word card: i.e. if you want to add "my car" to a sentence, you need an adjective card and a noun card, my and car; but because articles are so common and necessary, details doesn't require you to use a separate adjective card. You can just write the article on the same card as the noun: the car.

Almost all of the starting sentences in details will already have a subject, but it's often possible to add another. Example:

Flowers smell nice.

We can add another noun to the subject, and turn it into a "compound subject", but to do this we also need a conjunction.

Flowers and cookies smell nice.

If the sentence already has a compound subject (i.e. there's already a conjunction), we can add one or more extra nouns to the subject just by using commas.

Flowers, babies, coffee and cookies smell nice.

Almost every sentence in English has a subject¹, but not every sentence has an object. Objects are only needed with transitive verbs, i.e. verbs where something receives the action. Examples:

I hate the moon.

Alice ate apples.

Bob bakes bread.

As mentioned above, prepositional phrases also need objects, so if you have a preposition card, it would be a good idea to make sure you have a noun card to use with it: with milk.

Galactus ate the moon for breakfast.

There are (at least) three ways that nouns can be used as adjectives.

The possessive form

The possessive form of nouns functions as an adjective, but it's still a noun.

Sam broke Jack's laptop.

The crow's cawing kept me awake.

Turn a simple noun into a compound noun

"Lion" is a noun. "Sea lion" is also a noun. Sometimes you can add a noun in this way. Other times this is almost cheating —compare french fry with French perfume. Use your own judgment, and when in doubt, ACTD.

Expand on a proper noun

Proper nouns —the names of specific people, places and things— can often be expanded by adding a title, or just another random noun, and the result is still grammatically correct.

Carol sings beautifully.

can be changed to

Doctor Carol sings beautifully.

And we could transform

My friend Joe owns Rocket Records.

into

My friend Joe owns Lizard Rocket Records.