Senior Member
I don't quite understand the use of azt in sentences like 'Azt hiszem...', 'Azt mondom...' (I can't really think of another example right now but I'm sure there are a few). Are there verbs which always go with azt and you just have to add them? Though, I've seen the verb hisz used without azt which confused me further.
  • "Azt" is often used with verbs related to the mind and communication. They don't always go with "azt", but omitting it often makes the phrase less idiomatic (to a varying degree). You may think of "azt" as a kind of emphatic determiner, as in "what he said was that..." (= azt mondta, hogy...)

    Some common examples (in the past tense, 3rd person singular)
    (note that "hogy" is often omitted in spoken Hungarian):

    • írta, hogy... (he wrote)
    • hitte, hogy... (he thought/believed)
    • kérdezte, hogy... (he asked)
    • válaszolta, hogy... (he answered)
    • akarta, hogy... (he wanted)
    • gondolta, hogy... (he thought)
    • képzelte, hogy... (he imagined)
    • hazudta, hogy... (he lied)
    • tervezte, hogy... (he planned)
    So, if I said something like "Hiszem, (hogy) ez most kicsit sürgetőbb ..." instead of "Azt hiszem, (hogy) ez most kicsit sügertőbb ..." it wouldn't be grammatically incorrect per se, just "less idiomatic"?
    "Azt hiszem" is an everyday phrase to express an opinion, roughly the same as "I think". It's so common that many people pronounce it "asszem".
    "Hiszem" is possible, but in a different context: it sounds more formal or literary. It's closer to "I believe in...", when talking about religious/moral beliefs.

    With other verbs, the difference between the phrases with and without "azt" might be different. :)
    Azt hiszem, hogy szeret engem - I believe that she loves me... where believe is close to "I think" here. ("Ugy gondolom, hogy ...")
    Hiszem, hogy szeret engem - I believe that she loves me ... where it is more like "I do believe", "I believe and I strongly hope it is true".
    -- another version of the "azt hiszem - hiszem" difference. I'm not sure if there are such differences regarding the other words AndrasBP has listed.
    I think "Azt ... hogy" is the default, and the lack of "azt" sometimes conveys additional fine distinctions.