The adjective useful is commonly used to describe things that are in some way helpful or advantageous for a particular purpose: The recruiter provided the job seeker with a ton of useful information about the role. The synonym handy is a bit more informal and is used especially to talk about things that are convenient or that make things easier: The article was published alongside a handy glossary of terms so readers wouldn’t get lost in the technical terminology. Handy appears quite frequently in the phrase “come in handy,” as in, The article listed a bunch of tips and tricks that might one day come in handy.
When we describe someone as insensitive, we usually mean they are unfeeling or deficient in human sensibility, acuteness of feeling, or consideration: His glib remarks showed how insensitive he was. This descriptor implies a lack of awareness and responsiveness in thought and action. The synonym callous is more than just unaware or inconsiderate, it’s hardened to the point of cruelty. Callous means “unsympathetic” or “indifferent”: They have a callous attitude toward the sufferings of others. Its literal meaning is “made hard,” or “hardened,” as in the case of skin that has experienced repeated friction, resulting in a callus. Drawing on this earlier sense of the word, figurative uses of callous may imply that one is insensitive to hurt as the result of continued repression and indifference.
Interpret and construe are close enough in meaning that if you look them up in the dictionary, you might see them defining each other! But that’s not to say that there aren’t differences between the two. Interpret is the more common verb and it primarily means “to explain” or “to provide the meaning of,” as in the case of someone who interprets a symbol or interprets the hidden meaning in a written passage. More loosely, to interpret something is to make sense of it. Construe implies a bit more subjectivity or variety of perspective. To construe something is to deduce its meaning by inference, or to understand something in a particular way, especially in a legal context. It is related to the verb construct by way of Latin construere “to put together, build.” While that etymological tidbit is unlikely to help you win trivia night, it is helpful in remembering how to use this word: when you construe something you are, in a way, putting together its meaning or significance.