Naming/How to choose a foreign name

Different languages and societies use different names. When in a different society, one can either use one’s existing name, suitably adapted, or adopt a new name native to the society.

Which to use?
If one is visiting briefly, or the foreign society has similar names, or one’s existing name is at least pronounceable in the foreign language, there is no need to adapt a new name, but for extended stays or for societies with very different names or phonology, adopting a new name is often useful.

For instance, Japanese and Russian names are pronounceable with reasonable accuracy in English, and American society has many immigrants, so Japanese and Russian visitors and immigrants to the US have little need to adapt a new name, though some choose to.

By contrast, most English names are unpronounceable in (Mandarin) Chinese, and conversely Chinese names are unpronounceable in English (the lack of tones in English significantly distorting them), so many Chinese in the US and English-speakers in China adopt local names.

The use of multiple personal names is widespread in a number of societies; see for instance Names of Sun Yat-sen.

Daveandivan
"Close enough" (different European countries)

Societies with high immigration, such as the US (but names often changed at Ellis Island)

Brad Pitt to Buraddo Pitto (ブラッド ピット)

cognate (Grigory to Gregory/Greg)

New name
In choosing a new name, one can try to be close in meaning or in sound to one’s existing name, or can select an entirely new name.

Close to original
As an example of retaining meaning, one might adapt English (general European, from Greek) Nicholas, meaning "victory of the people", to Japanese Katsu, meaning "victory".

As an example of a similar sound, one might adapt English (general European, from Greek) Margaret or "Maggie", to Japanese "Megumi".

Beware that trying to hew too closely to the meaning or sound of one’s existing name can yield a name that sounds artificial. For instance, Chinese given names are ordinary words, while very few English given names have recognizable meanings (the original meanings lost with time), so a Chinese person seeking an English name that is also an ordinary word will be choosing from a small and unusual subset of names (largely virtue names such as “Grace”, or flower names such as “Lily”). Similarly, using names that incorporate unusual sounds (that are close to the original language) will yield unusual-sounding names. For instance, initial "Yu" or "Eu" sounds are common in Korean and Japanese names, but quite rare in English ("Eugene" and "Eunice" being the only relatively common examples).

Entirely new
In choosing an entirely new name, one has much the same considerations as with naming a child, with certain differences such as:
 * Identity: as one is naming oneself, one has an idea of one’s own identity, which a baby receiving a name from a parent does not.
 * Lack of familiarity: one generally adopts a name when first moving to or joining a society, when one is yet unfamiliar with local names.

Thus one would suggest similar considerations to naming a child, with particular attention to:
 * Frequency of name: without an intuition of frequency, one may unwittingly choose a very standard name such as YAMADA Hanako (equivalent of Jane Smith), or a very unusual one, without this being one’s intention.
 * Soliciting opinions from native speakers: who will have greater intuition about what sounds pleasing.