I don’t know to what aspect of the language you are referring, but, simply put, the structure would refer to the units which make up the language, nouns, verbs, adjectives, etc. and the way they are combined into sentences. Function would refer to the purpose of the sentences, what ideas are meant to be conveyed. The function of a sentence could be a statement, a command, a question or an exclamation. I don’t know if that’s the answer you’re looking for but I hope it helps.

Hello ! I hope you are ok like I wish you that. Take the difference: Function: 1. purpose: an action or use for which something is suited or designed Its function is to collect water. a watch with an alarm function 2. role: an activity or role assigned to somebody or something 3. event: a social gathering or ceremony, especially a formal or official occasion a black-tie function 4. dependent factor: a quality or characteristic that depends upon and varies with another Success is a function of determination and ability. 5. mathematics variable quantity: a variable quantity whose value depends upon the varying values of other quantities 6. mathematics correspondence between members of different sets: a relationship between two mathematical sets, in which each member of one set corresponds uniquely to a member of the other set. Symbol f 7. comput single computer operation: a named and stored basic operation of a computer yielding a single result when invoked 8. comput computer program's main purpose: the purpose of a computer program or piece of computer equipment, e.g. database management or printing 9. grammar role of word or phrase: a grammatical role performed by a word or phrase in a specific construction Noun phrases can fulfill many functions.

So by conclusion Function is the purpose that something has, or the job that someone or something does During structure is the way in which the parts of something are connected with each other and form a whole, or the thing that these parts make up

Pursuit Structure: 1. something built or erected: a building, bridge, framework, or other object that has been put together from many different parts 2. system of parts: a system or organization made up of interrelated parts functioning as a whole 3. way that parts link or function: the way in which the different parts of something link or work together, or the fact of being linked together the structure of local government The essay is interesting, but it lacks structure. 4. biology part of organism: a part of a body or organism identifiable by its shape and other properties, e.g. tissue or an organ 5. chemistry arrangement of atoms: the arrangement of atoms in a molecule 6. geology component parts of rocks: the physical disposition of a rock mass or its mineral components