A combination of that and brief flashes of visual imagery.

I'm definitely an internal-monologue thinker. I've tried breaking myself from it and going into pure thought(which feels like it ought to be an option, because I know how the sentence I'm thinking will end when I'm halfway through, and I've successfully tested breaking monologue and still proceeding with the mental understanding of what I was going to think), but I spend more time thinking "No! Stop monologuing!" than I save by not monologuing.

The most common for me are verbal (if I think while taking a walk, I basically talk to myself), spatial/kinesthetic (which key on my ring goes to this door again?), and visual/symbolic (integrate Sin(Ln(x))/x dx). But there's plenty more stuff I'd call thinking.

Verbal and symbolic thinking are often just expressions of conceptual problem-solving, where my brain can actually fit concepts together rather than just talking. Like in the integral above - I pattern-match it to the general concept "change of variables," without using words or symbols, and then after a second or so of brewing I can examine the idea in terms of symbols and words.

I experience a thought all at once, usually without words or images. I sometimes reflexively start verbalizing thoughts internally at a spoken-conversation rate. I tend not to think of this inner monologue as the content of my thought but some incidental surface activity. It trails off after a couple words, since I already knew the entire verbalization before I even started inner-monologuing it.

Visualization and imagined conversations both feel very different from this and from each other.

Folks who are more verbal: do you talk to yourself in real time? How does reading feel in comparison? When you recall a conversation, do you re-verbalize the content? Can you speak without knowing what you're about to say beforehand? (I'm pretty sure I can't.)

Most idle thought comes across as a mental conversation.

Math (Calculus, Numeric Methods, structural design stuff, not actually numbers) is visualized as shapes, patterns, trends.

And decision making is more felt than anything else, where the attractiveness, consequences, and uncertainty of opposing ideas are weighted side my side.

Often times it doesn't feel like anything. I just tell my mind to think about something, pause and wait while it's thinking, and then ask for the best answer.

Mostly like that, with things mentioned in the other replies occasionally interspersed, their admixture varying depending on what kind of topic I'm thinking of, and my mental state (whether I'm fatigued, whether I've been reading a lot in the past couple days, whether I've been drinking, etc.)

I also think primarily verbally, but I have a friend who thinks (in their own words) "in raw abstract thoughts interspersed with occasional dialogue and imagery."

Mine is more like a congress, where I have multiple "me's" having a conversation on a topic offering ideas and alternative hypotheses.

I call it thought qualia, because it is something I clearly experience but it is a sensory qualia. (Interestingly, this is the first time I'm using the term in public). It can have sensory conotations, though, and I sometimes have thoughts which are clearly verbal or visual.

When I'm not in the mood to talk to people- not out of anger, I'm just not feeling a desire to share my thoughts- I think in pictures and feelings with a reticent, sarcastic monologue. When I'm alone but feeling social, my monologue is wordy and sometimes witty. When I'm in a conversation, I often have to stop talking for a moment to think through what I'm going to say before I can say it.

Bottom line, I almost always have some kind of monologue; sometimes it's talkative, sometimes nearly silent.

I feel a narrative that goes along with my thinking but does not seem to me to be the thinking itself. I do a lot of my work visually, when I am on a roll I will generate 100s of matlab plots a day as part of my sorting through stuff. Certainly as I look at the plots I narrate what I think I'm seeing, but it seems that what I think I'm seeing comes before my pushing that into narration comes. So I think I actually do some of my thinking visually, but it is hard to put how that feels in to words. Maybe as a movie script?

It makes sense that your thinking could be both wordy and picturey, and even audio (non-words). And even body feel. From my reading (suggest Jeff Hawkins book on the brain) thinking activity shows up as activity in verbal and visual areas of the brain.

Some mixture of verbal thinking, and what I can only really describe as 'thinking in rules'.