In spoekn language, we often don't connect things much. 'I went home early...I was tired'- in written language, we use more conjunctions and things to link the language up, so look for examples of that. We often repeat things, so adverbs like very/really etc can be used a lot, where we would look for alternatives in writing. Speech chops and changes- we start of saying something one way the drift to another, often signalling the change with a pause and/or something like 'well'. Look for discourse markers and phatic speech. If it's something like Big Brother, look for slang and swearing.