Linguists have noted that a feature of London English is spreading further throughout Britain, especially among young people. Some speakers pronounce words such as "thing" as "fing", or "those" as "vose". The difference from Standard English (Received Pronunciation) occurs at which level of language? *

Morphology
Syntax
Phonology
Pragmatics

At the phonological level it is a basic change influenced by internal factors, related to articulatory properties or ease of articulation such as phonetic assimilation, dissimilation and other phenomena such as the epithesis or elision of sounds.

It has also been mentioned that languages can change due to external factors such as the influence of the linguistic substratum, which occurs when speakers of another language acquire the new language as the usual language of communication by carrying phonetic features of their old language. Although technically that would be the creation of a new variety in historical linguistics that type of changes is considered as one of the possible factors of diversification, and therefore “change” of a language. Linguistic levels of language

The Phonetics/ phonology,

It is the branch of linguistics that studies the production and perception of the sounds of a language in its physical manifestations. Its main branches are: experimental phonetics, articulatory phonetics, phonetics and acoustic phonetics.

Experimental Phonetics

It is the one that studies the oral sounds from the physical point of view, gathering and quantifying the data on the emission and production of the sound waves that configure the articulated sound .

The set of data analyzed when measuring sounds depends solely on the accuracy of the instruments as well as other related knowledge. Important differences have also been discovered in each oral sound.

Articulatory phonetics Linguistic levels of language

It is the one that studies the sounds of a language from the physiological point of view, that is, it describes which oral organs are involved in its production, in what position they are and how these positions vary the different paths that can follow the air when it comes out of the mouth, nose, or throat, so that different sounds are produced.

The organs involved in the articulation of sound are mobile or fixed: The lips, jaw, tongue and vocal cords are mobile, sometimes referred to as articulatory organs. With his help the speaker modifies the air outlet that comes from the lungs. The teeth, the alveoli, the palate and the veil of the palate are fixed. The sounds are produced when two articulatory organs are contacted, for example, the bilabial (p), which requires contact between the two lips.