The rules that determine how sounds and words can be combined and used to communicate meaning within a language are collectively known as

Phonology.

Explanation:

Phonetics and phonology are two complementary branches of linguistics and their primary domain of study are sounds. Phonetics studies sounds as acoustic units, independent of their use and meaning.

The concern of phonology, on the other hand, are those same sounds as elements of a system that is a language. Phonology examines the way that sounds (phonemes) are used and combined in order to create meaning and transmit intelligible messages.

the group received an extra pound of butter for christmas.

the annex was delighted to hear that we'll all be receiving an extra quarter pound of butter for christmas.

you should ask "yourself is it good enough? "