nit-picking - as someone who has spent some time hunting, finding and picking nits, I appreciate this term. Not that it matters too much for this metaphor, the nits aren't the beasts. The nits are the eggs and are actually easier to find than the lice who lay them, because nits are a rather beautiful creamy translucent colour. No matter. Nit-picking in writing is that usually irritating habit of picking up on people's minor errors, or spending rather too much time on minor points and missing the main drift. I rather like the way people say 'nit-picky' as an adjective: 'I don't want to be too nit-picky about this, but I would just like to say...'
big up - Did this start appearing in the UK around 1995? I have the impression that superannuated music journos started using it around then when talking about musicians and singers who probably didn't need to be bigged up by superannuated music journalists. You can say, 'a big-up for Mick Jagger' or 'I'm gonna big up Mick Jagger here...' . Shakespeare used it when Mark Antony says, 'I come not to bury Caesar, not to big him up' - very moving it is too.
butt out - this is the opposite of butting in, which is what goats do. If you've ever seen or felt a goat butting in, you get the picture. My step-daughter (aged about 9) was butted so hard, the goat pushed her up against a wall and held her there until its owner got it to, well yes, 'butt out', which showed that goats don't butt out of their own accord. In the US 'butt' is also the UK 'bum' or 'arse' and because of US imports, now everyone knows the US 'butt'. This means that 'butt out' now has an extra connotation of getting your bum out of the conversation and not just your horns. When I was in the sixth form, the way to command someone to stop intervening in a conversation was to deliver the command, 'Trunk out!'. This usage seems to have been restricted to Watford in the early 1960s.
blather, blether, witter - we seem to need quite a few words to describe what we think is load of nonsense or a lot of inconsequential chat. We might say, 'Oh there's me wittering on'. Or 'He was blethering on about something or another.' My father always said 'blather' as in 'Some load of old blather' and 'blether' has a strong Irish sound in my ears as I've heard plenty of Irish people saying it almost as 'blethrr'. People in Much Wittering are sick and tired of people asking them if....so I won't.
effective - occasionally this rhetoric of modern terms will sneak in a bit of education-ese. In the hours of compulsory comprehension that we all enjoy so much, one repeated question is 'why do you think this phrase is effective?' You might be thinking that it isn't 'effective' but the question side-steps any possibility that you might think the phrase is boring and crap. The answer is usually something to do with alliteration, personification, metaphor or simile which you can remember with the mnemonic SPAM. This will save you ever wondering why or how alliteration, personification, metaphor and simile might be 'effective'. They just are. Like high mountains. Being good at English Literature when you're 16 is about doing this without thinking. Being good at English Literature at 18, 21 and for MAs and Ph.Ds is avoiding at all costs saying that a piece of writing is 'effective'.
connectives - this is an exciting new word to come into school vocabulary, and talking of vocabulary, connectives are part of the mnemonic VCOP which has only a slight connection with the police (the school inspection service) and stands for vocabulary, connectives, openers, punctuation. Apparently, these were what were deficient in thousands of examples of children's writing, when examined by researchers. So children now sit down to write, saying to themselves (or teachers say it to them), 'VCOP!' The connectives are a grammatical pot-pourri of words which perform different functions in sentences, some of them 'conjunctions' (and, but, etc), some of them what used to be called 'sentence adverbs' (however, eventually, etc) and some of them the 'header' words for 'subordinate clauses' (when, if etc). You could argue that there are many other kinds of 'connectives' in sentences eg 'this' or 'it' which usually connect to something that comes before it, after it, or to some strange 'it-ness' belonging to the world, as in 'It was sunny.' But the rule here, is never question grammatical terminology too closely or the whole apparatus will collapse (eg 'adverbs' quite often don't do anything to verbs eg 'very' in 'I am being very silly about this.'). Still [connective], let's not get too het up about this [not a connective].