Adolescence /ˌæd

concept /ˈkɒn.sept/ /ˈkɑːn-/ noun [ C ]
1. a principle or idea
The very concept of free speech is unknown to them.
It is very difficult to define the concept of beauty.
I failed to grasp the film's central concept.
Kleenbrite is a whole new concept in toothpaste!
2. not have any concept/have no concept of sth
to not understand about something
I don't think you have any concept of the pain you have caused her.
conjecture /kənˈdʒek.tʃə r / /-tʃɚ/ noun [ C or U ]
(the forming of) a guess about something based on how it seems and not on proof
There's been a lot of conjecture in the papers recently about the royal marriage.
dialect /ˈdaɪ.ə.lekt/ noun [ C or U ]
a form of a language that people speak in a particular part of a country, containing some different words and grammar, etc.
a regional dialect The poem is written in northern dialect.
fluent /ˈfluː.ənt/ adjective
1. When a person is fluent, they can speak a language easily, well and quickly
She's fluent in French. He's a fluent Russian speaker.
2. When a language is fluent, it is spoken easily and without many pauses
He speaks fluent Chinese.
fluency /ˈfluː.ən t  .si/ noun [ U ]
One of the requirements of the job is fluency in two or more African languages.
fluently /ˈfluː.ənt.li/ adverb
I'd like to speak English fluently.