English has three nasal consonants, /n/, /m/, and /ŋ/. The last is a velar nasal and is called “eng” by phoneticians, pronounced just the way it’s written, i. e., [ɛŋ], as in the first syllable of Engels. This is the sound that appears in participles/gerunds written with the suffix {-ing}, as in going, happening, etc.

In many English dialects on both sides of the Atlantic, the eng is replaced by the dental nasal {-n], which is typically rendered orthographically with an apostrophe after the n, signifying the missing velarity of the norm. This phenomenon is referred to as “dropping one’s g‘s.” Historically, this pronunciation is of some antiquity and was the older norm in England for all stylistic registers. After around the turn of the twentieth century, doubtless under the influence of the spread of literacy, standard English began to adhere to the form with eng where dialects maintained the simple nasal. In American English there are many regions (like the American South) where speakers who adhere to the norm in every other respect have a dental rather than a velar nasal in participles and gerunds.

Many speakers  can switch between the norm and a regional version when they wish to maintain a colloquial stylistic register, as in informal speech. For purposes of public speaking, as by politicians and others who need to ingratiate themselves with their audiences, the eng is typically simplified to an n. This gives utterances a colloquial flavor.

One speaker who regularly does this kind of intra-code switching is Barack Obama. In his public appearances he can be heard laying on the englessness as a means of staying in a colloquial mode, the better to ingratiate himself with audiences he must reckon to be composed largely of speakers who need to be catered to linguistically as well as in other respects. Tant pis!