I've been thinking that if I ever take over the world and unify us in language, there will be a few changes to English.
First, what "we" means will be broken into 2 different words (same with "us"). One for meaning the speaker and the listener (and maybe others), one for meaning the speaker and others but not the listener. So "he invited us" will be clear to the listener if he invited the speaker and someone else, or the speaker and the listener. "We'd better go" would let you know if you're supposed to go too, or if the speaker is leaving with someone else.
Second, there will be a special word for that random hair that you can feel stuck to your shirt and occasionally brushing against your arm. It has to be one of the most irritating feelings.
Third, there will be multiple words to represent love -- there will be one word for romantic love, one word for family/friend love (and pets), one word for one-sided love from afar, and one word for feelings toward inanimate objects (like I love pizza wouldn't mean saying the same word as how you feel about your mom or your husband).
I may have to come back and supplement this list as time goes on, but those are the three prominent deficiencies in our language that I've been thinking about lately. Much nicer than yesterday already.