There is a slight difference. Even if it is only subtle. Most of the time either will do. The main difference would be if you are thinking more in depth about something then you would say you are "thinking about it." You would be actively thinking about it (considering options, what if...) eg. "I'm thinking about when I learnt to drive." If you are "thinking of" something it is more of a passing thought. eg. "I'm thinking of a number between 1 and 10" You aren't really thinking about the number, only in the sense that it exists at all. Most of the time either can be used "I'm thinking about/of shutting the door." Either of these make perfect sense and nobody would question them. To conclude. It probably doesn't matter most of the time. But in general to think about something is to think in more depth (perhaps considering is accurate here.) Thinking of is to just recall/come up with something. Or to simply have it on your mind (not much thinking involved) Final example. To think of an idea is to come up with a new idea, to think about an idea is to consider one that has already been created. Think of = invent/recall. Think about = consider/actively wonder. Hope this helps :)

Great question. Here are some subtle differences: "Of" usually implies that you're not very familiar with something (or someone), have thought about something for a short period of time, or express uncertainty about a particular topic. Example: Did you think of co-parenting? (Meaning: Did it occur to you that co-parenting is an alternative to marriage?) Example: I know of Johnny. (Meaning: I know that Johnny exists and I know what he looks like, but I don't know his personality that well.) Example: I thought of trying that. (Meaning: I thought of trying that, and I tried it even though I wasn't sure if it'd work.) Example: I thought of doing that. (Meaning: I thought of doing that, but I didn't do it because I wasn't sure if it'd work.) "About" implies that you're very familiar with something (or someone), have thought extensively about something, or express certainty about a particular topic. Example: Did you think about marriage? (Did you consider it's pros and cons?) Example: I thought about the teacher's lesson, and it made perfect sense. (I thought about all the points that the teacher made & understood them.) Example: Did he think about the consequences of his actions? (Did he think about the moral consequences of his actions and how it impacted other people?)

They are the same thing, you can use either one. Example: *I think about my cat everyday. *I think of my cat everyday.

There's no difference.