Spelled jumping, pronounced /ˈdʒʌmpɪŋ/.
The -ing ending is spelled i, n, g and pronounced /ɪŋ/. No silent letters and no spelling changes from jump.
Spelled jumping, pronounced /ˈdʒʌmpɪŋ/.
The -ing ending is spelled i, n, g and pronounced /ɪŋ/. The base word jump keeps its spelling unchanged, so all three letters of the ending simply follow it. No silent letters appear, and the /mp/ sound stays clear before the /ɪŋ/ ending, as in /ˈdʒʌmpɪŋ/.
One small trap: the g in -ing is fully pronounced, /ŋ/, a single nasal sound, not /ŋg/ as in finger. Still write all three letters, i, n, g.
British and American speakers both say /ˈdʒʌmpɪŋ/. In casual speech the ending may sound like [ɪn], but the spelling stays i-n-g.
In jumping, written j-u-m-p-i-n-g, the p is not silent: /mp/ stays clearly audible, then the ending /ɪŋ/.
Spelled j-u-m-p-i-n-g, matching the sounds in order: /ˈdʒʌm/ plus /ɪŋ/. Only the first syllable carries stress, /ˈdʒʌm/, and the ending is /ɪŋ/.