The Spanish adjective 'larga' (feminine form of 'largo', meaning 'long') comes from the Latin word 'largus', which meant 'abundant' or 'copious'. The semantic shift from the Latin meaning of 'abundant/copious' to the Spanish meaning of 'long' likely occurred because something that is long can be thought of as extending abundantly in space. The feminine form 'larga' is used when describing feminine nouns in Spanish, following Spanish grammatical gender rules.

The masculine form 'largo' is very common in Spanish and means the same thing - 'long'. You'll often hear phrases like 'tiempo largo' (long time) or 'pelo largo' (long hair). Another related word is 'largarse' which is a reflexive verb meaning 'to leave/get out' - the connection being the idea of making oneself 'long gone'.

While English 'long' is not etymologically related (it comes from Germanic roots), we do have some English words from Latin 'largus'. The most obvious is 'large', which retained more of the original Latin sense of 'abundant/copious' but shifted to refer specifically to great size. We also have 'largesse', meaning 'generosity', which comes from the same Latin root through French - the connection being that someone who is generous gives abundantly.