The Spanish word 'blando', meaning 'soft' or 'weak', comes from the Latin word 'blandus', which meant 'flattering' or 'caressing'. The semantic shift from 'flattering/caressing' to 'soft' is quite intuitive - something that caresses tends to be soft or gentle to the touch. Over time, this physical quality of softness became the primary meaning in Spanish, while the metaphorical sense of 'flattering' was lost.

A common related Spanish word is 'ablandar' which means 'to soften' or 'to make soft'. This verb is formed by adding the prefix 'a-' and the verbal suffix '-ar' to 'blando'. You might also encounter 'blandura' meaning 'softness' or 'gentleness'.

While English doesn't have many common words directly related to Latin 'blandus', we do have 'bland', which comes from the same Latin root. Interestingly, while Spanish retained the meaning of physical softness, English 'bland' developed to mean 'mild' or 'lacking strong features' - you can see how both meanings evolved from the idea of something gentle or non-aggressive. The English word 'blandishment', meaning 'flattery' or 'coaxing speech', preserves more of the original Latin meaning of 'flattering'.