Dōu 都 ‘all; both’ is an adverb, which mostly occurs after the subject and before the main verb or adjective in a sentence. It is used to indicate inclusiveness – that is, all items within the subject or object share the same characteristic.

Structure
Basic form
Dōu 都 ‘all; both’ is mostly placed after the subject and before the main verb or adjective in a sentence.
Negation
Negation can occur in front of dōu 都 or behind dōu 都, depending on what is negated in the sentence. If a negation adverb is placed in front of dōu 都, it means ‘not all’; if behind dōu 都, it means ‘both/all are not doing something’. See the comparison:
Question
To form a yes-no question, put the question particle ma 吗/嗎 at the end of the sentence.
With objects at the beginning of the sentence
If dōu 都 refers to the object, the object needs to be placed at the beginning of the sentence.
With adverb yě 也
When yě 也 ‘also’ co-occurs with dōu 都, dōu 都 should be placed after yě 也.
With other adverbs
When other adverbs are co-occurring with dōu 都 such as hěn 很 ‘very’, dōu 都 should be placed before these adverbs.
With a prepositional phrase
When a prepositional phrase occurs in the sentence, dōu 都 is usually placed before the prepositional phrase and refers to the subject.
When a prepositional phrase occurrs in the sentence, dōu 都 is usually placed before the prepositional phrase and refers to the subject.
Functions
Dōu 都 expresses ‘inclusiveness’
Dōu 都 indicates that all items of the subject or object have something in common—do the same action or have the same quality. This shared characteristic is expressed by the predicate, a verb, or an adjective. It can be translated as “both” if there are two subjects or objects. If there are more than two, we translate it as ‘all’.