user13587: I’ve been reading about this term and have found it written in both ways. I don’t know if the difference is related to some kind of verb form.

user254: This dictionary says that yathābhūta
 is an adjective, whereas yathābhūtaṃ is an adverb
I haven't seen how yathābhūta is used in practice. Where is yathābhūta even used? I can only find yathābhūtaṃ. 
But grammatically I presume that an "adjective" would qualify a noun (e.g. "he sees a true thing"), whereas an "adverb" qualifies a verb (e.g. "he truly sees a thing").

I know the blank space might change the context, but I've found the 4 variations, so I'm hopping you know something more about this
I don't know about the Pali scripts, but in some scripts there are no blank spaces in the script, forexamplethetextiswrittenlikethis and it's up to the reader to know where each word ends (I think it's like that when you have to understand any spoken language too).
Furthermore (or rather, more importantly), Pali (like German) has compound words.
English has some compound words too, like "butter knife" and "farsighted".
So for example SN 12.23 includes:

I say that truly knowing and seeing has a vital condition.
  Yathābhūtañāṇadassanampāhaṃ, bhikkhave, saupanisaṃ vadāmi, no anupanisaṃ.

More literally:
"Truly-knowing-and-seeing, monks, I say, is not without a condition."
To translate a long, compound word like "Yathābhūtañāṇadassanampāhaṃ" you deconstruct it into its various component root words.

I have two more questions: Can yathābhūta be used as a term or should it be always used in a sentece? If it can be used as a term, how would you translate it?
Dictionary definitions of the roots of the word are:

Yathā (i.e. "according to" or "in accordance with")
Bhūta (i.e. "natural", "genuine", "true").

So "according to the truth" or "true" or "truly" is a common translation.
Bhūta also apparently means things like "creatures", "beings", "biological kingdoms", "elements" -- so I might translate it as "seeing things according to their nature", or "seeing the nature of thing" (or, possibly, "naturally seeing things" or "seeings things naturally").
It could be translated "seeing things in their proper categories" -- for example AN 4.179 ...

Reverend Ānanda, it’s because some sentient beings don’t really understand which perceptions make things worse, which keep things steady, which lead to distinction, and which lead to penetration.

... talks about "really understanding" whether a perception belongs to one of three or four categories.
It also means "everything", "nature", and "the result of becoming" -- so it might mean "seeing things as natural".
Buddhism has a lot to say about "all created things" (e.g. it says sabbe sankhara anicca) ... so perhaps that too should be included in the view (see e.g. SN 22.55).
According to the context in which it's used (in sentences, in suttas), it's often associated with samadhi and enlightenment.

user10100: Yathābhūta is not correct in pali-sentence. We have to put the declension-mark at the end of yathābhūta, such as  yathābhūtaṃ, before put it in the sentence.
Yathābhūta is adjective/adverb which is not complete, not ready to use, because the properties of word (vibhatti;case-endings;declension):  preposition(sambandha), amount(vacana), and gender(liṅga), etc., must put at the end of every words, except ready-made-noun (nipāta), some standalone-prefix (upasagga-nipāta; I'm not sure for linguistic name), and compound-word (samāsa). So, it can not come alone, and you can not found only yathābhūta  alone in pāli. It should to be yathābhūtaṃ (si-vibhatti), yathābhūtañāṇadassanaṃ (Deleted vibhatti because of compound-word; Vibhatti still be, but it disappear by pali-processing), yathābhūtena (nā-vibhatti), etc.
See: http://www.buddha-vacana.org/toolbox/noundec.html
For the explanation of the term "yathābhūta":
Yathā ... tathā = How it is ... as it is.
Bhūta = arising/becomming = upatti-bhava-paṭiccasamuppāda = upatti-becoming = jāti(rebirth) + jarā&maraṇa (old-age&death). bhū-root[as arise-term]+ta-suffix[as verb].
Arising of what? Arising of 5 aggregates in paṭiccasamuppāda-cycle. So: 

in Sutta. Saṃ. Saḷa. Dukkhadhammasutta, buddha use yathābhūta
as arising and vanishing of 5 aggregates;
In Sutta. Saṃ. Ni. Dukkhasutta, buddha describe arising and
vanishing of 5 aggregates as paṭiccasamuppāda;
In Khandhapabba of Sutta. Ma. Mū. Mahāsatipaṭṭhānasutta, 
buddha describe arising and vanishing of 5 aggregates as
udayabbaya-ñāṇa-niddeso;
Also, in Khandhapabba, buddha describe vipassanā in arising
and vanishing of 5 aggregates as "samudayavayadhammānupassī
vā" which commentary refer that dhamma-term as
Dukkhadhammasutta;
So, in Sutta. Khu. Paṭisambhidāmaggo
udayabbayānupassanāñāṇa-niddesa & the path of purification
maggāmaggañāṇadassanavisuddhiniddesa udayabbayañāṇakathā, Master
Sāriputta and Master Buddhaghosa describe udayabbaya as
paṭiccasamuppāda as well.

So, yathābhūta-ñāṇa is understanding of arising of 5 aggregates in paṭiccasamuppāda-cycle. 
Another, I also describe yathābhūta in this answer: https://buddhism.stackexchange.com/a/26702/10100
Buddha have to cut the big sutta in DN/MN for the students who not smart enough to enlighten/understand/memorize at once. So, you can notice my reference are from DN&MN&SN&KN, and actually AN as well.
Pāli has a very strong structure. This is the reason why we can understand tipitaka's content by just fluent reciting&memorizing. But because of the complicate detail of Dhamma, so when we translate tipitaka to the other languages, such as english or especilly thai, we will lose many important words' properties. Then we can not understand/analysis/find the fact from some translation.
"Svākkhāto bhagavatā dhammo-the best dhamma was taught by buddha." is not just the psalms, but it is the fact by the linguistics and the truth.

13587: <p>I’ve been reading about this term and have found it written in both ways. I don’t know if the difference is related to some kind of verb form.</p>
 254: <p>This dictionary says that <a href="https://suttacentral.net/define/yath%C4%81bh%C5%ABta" rel="nofollow noreferrer">yathābhūta
</a> is an adjective, whereas <a href="https://suttacentral.net/define/yath%C4%81bh%C5%ABta%E1%B9%83" rel="nofollow noreferrer">yathābhūtaṃ</a> is an adverb</p>

<p>I haven't seen how <em>yathābhūta</em> is used in practice. Where is <em>yathābhūta</em> even used? I can only find <em>yathābhūtaṃ</em>. </p>

<p>But grammatically I presume that an "adjective" would qualify a noun (e.g. "he sees a <em>true</em> thing"), whereas an "adverb" qualifies a verb (e.g. "he <em>truly</em> sees a thing").</p>

<hr>

<p><strong>I know the blank space might change the context, but I've found the 4 variations, so I'm hopping you know something more about this</strong></p>

<p>I don't know about the <a href="https://en.wikipedia.org/wiki/Pali#Writing" rel="nofollow noreferrer">Pali scripts</a>, but in some scripts there are no blank spaces in the script, forexamplethetextiswrittenlikethis and it's up to the reader to know where each word ends (I think it's like that when you have to understand any spoken language too).</p>

<p>Furthermore (or rather, more importantly), Pali (like German) has <a href="https://dhamma.ru/paali/Pali_compounds.htm" rel="nofollow noreferrer">compound words</a>.</p>

<p>English has some compound words too, like "butter knife" and "farsighted".</p>

<p>So for example <a href="https://suttacentral.net/sn12.23/en/sujato" rel="nofollow noreferrer">SN 12.23</a> includes:</p>

<blockquote>
  <p>I say that truly knowing and seeing has a vital condition.<br>
  Yathābhūtañāṇadassanampāhaṃ, bhikkhave, saupanisaṃ vadāmi, no anupanisaṃ.</p>
</blockquote>

<p>More literally:</p>

<p>"Truly-knowing-and-seeing, monks, I say, is not without a condition."</p>

<p>To translate a long, compound word like "Yathābhūtañāṇadassanampāhaṃ" you deconstruct it into its various component root words.</p>

<hr>

<p><strong>I have two more questions: Can yathābhūta be used as a term or should it be always used in a sentece? If it can be used as a term, how would you translate it?</strong></p>

<p>Dictionary definitions of the roots of the word are:</p>

<ul>
<li><a href="http://dsalsrv02.uchicago.edu/cgi-bin/philologic/getobject.pl?c.3:1:264.pali" rel="nofollow noreferrer">Yathā</a> (i.e. "according to" or "in accordance with")</li>
<li><a href="http://dsalsrv02.uchicago.edu/cgi-bin/philologic/getobject.pl?c.2:1:3646.pali" rel="nofollow noreferrer">Bhūta</a> (i.e. "natural", "genuine", "true").</li>
</ul>

<p>So "according to the truth" or "true" or "truly" is a common translation.</p>

<p><em>Bhūta</em> also apparently means things like "creatures", "beings", "<a href="https://en.wikipedia.org/wiki/Kingdom_(biology)" rel="nofollow noreferrer">biological kingdoms</a>", "elements" -- so I might translate it as "seeing things <em>according to their nature</em>", or "seeing the nature of thing" (or, possibly, "naturally seeing things" or "seeings things naturally").</p>

<p>It could be translated "seeing things in their proper categories" -- for example <a href="https://suttacentral.net/an4.179/en/sujato" rel="nofollow noreferrer">AN 4.179</a> ...</p>

<blockquote>
  <p>Reverend Ānanda, it’s because some sentient beings don’t really understand which perceptions make things worse, which keep things steady, which lead to distinction, and which lead to penetration.</p>
</blockquote>

<p>... talks about "really understanding" whether a perception belongs to one of three or four categories.</p>

<p>It also means "everything", "nature", and "the result of becoming" -- so it might mean "seeing things <em>as natural</em>".
Buddhism has a lot to say about "all created things" (e.g. it says <em>sabbe sankhara anicca</em>) ... so perhaps that too should be included in the view (see e.g. <a href="https://suttacentral.net/sn22.55/en/sujato" rel="nofollow noreferrer">SN 22.55</a>).</p>

<p>According to the context in which it's used (in sentences, in suttas), it's often associated with samadhi and enlightenment.</p>
 10100: <p>Yathābhūta is not correct in pali-sentence. We have to put the declension-mark at the end of yathābhūta, such as  yathābhūtaṃ, before put it in the sentence.</p>

<p>Yathābhūta is adjective/adverb <strong>which is not complete, not ready to use</strong>, because the properties of word (vibhatti;case-endings;declension):  preposition(sambandha), amount(vacana), and gender(liṅga), etc., must put at the end of every words, except ready-made-noun (nipāta), some standalone-prefix (upasagga-nipāta; <em>I'm not sure for linguistic name</em>), and compound-word (samāsa). So, it can not come alone, and you can not found <strong>only yathābhūta</strong>  alone in pāli. It should to be yathābhūtaṃ (si-vibhatti), <strong>yathābhūta</strong>ñāṇadassanaṃ (Deleted vibhatti because of compound-word; Vibhatti still be, but it disappear by pali-processing), yathābhūtena (nā-vibhatti), etc.</p>

<p>See: <a href="http://www.buddha-vacana.org/toolbox/noundec.html" rel="nofollow noreferrer">http://www.buddha-vacana.org/toolbox/noundec.html</a></p>

<h2>For the explanation of the term "yathābhūta":</h2>

<p>Yathā ... tathā = How it is ... as it is.</p>

<p>Bhūta = arising/becomming = <strong>upatti-bhava-paṭiccasamuppāda</strong> = upatti-becoming = jāti(rebirth) + jarā&amp;maraṇa (old-age&amp;death). bhū-root[as arise-term]+ta-suffix[as verb].</p>

<p>Arising of what? Arising of 5 aggregates in paṭiccasamuppāda-cycle. So: </p>

<ol>
<li>in Sutta. Saṃ. Saḷa. <a href="http://www.84000.org/tipitaka/pitaka_item/r.php?B=18&amp;A=5092&amp;eng=accesstoinsight_wlsh" rel="nofollow noreferrer">Dukkhadhammasutta</a>, buddha use yathābhūta
as <strong>arising</strong> and <strong>vanishing</strong> of 5 aggregates;</li>
<li>In Sutta. Saṃ. Ni. <a href="http://www.84000.org/tipitaka/read/r.php?B=16&amp;A=1920&amp;eng=suttacentral" rel="nofollow noreferrer">Dukkhasutta</a>, buddha describe arising and
vanishing of 5 aggregates as <a href="http://84000.org/tipitaka/read/v.php?B=10&amp;A=1455&amp;Z=1887&amp;eng=metta_e2" rel="nofollow noreferrer">paṭiccasamuppāda</a>;</li>
<li>In <a href="http://www.buddha-vacana.org/sutta/digha/dn22.html#4B" rel="nofollow noreferrer">Khandhapabba</a> of Sutta. Ma. Mū. Mahāsatipaṭṭhānasutta, 
buddha describe arising and vanishing of 5 aggregates as
udayabbaya-ñāṇa-niddeso;</li>
<li>Also, in <a href="http://www.buddha-vacana.org/sutta/digha/dn22.html#4B" rel="nofollow noreferrer">Khandhapabba</a>, buddha describe vipassanā in <strong>arising</strong>
and <strong>vanishing</strong> of 5 aggregates as "samudayavaya<strong>dhammā</strong>nupassī
vā" which commentary refer that dhamma-term as
<a href="http://www.84000.org/tipitaka/pitaka_item/r.php?B=18&amp;A=5092&amp;eng=accesstoinsight_wlsh" rel="nofollow noreferrer">Dukkhadhammasutta</a>;</li>
<li>So, in Sutta. Khu. Paṭisambhidāmaggo
<a href="http://www.84000.org/tipitaka/read/roman_read.php?B=31&amp;A=1545" rel="nofollow noreferrer">udayabbayānupassanāñāṇa-niddesa</a> &amp; <a href="https://www.accesstoinsight.org/lib/authors/nanamoli/PathofPurification2011.pdf" rel="nofollow noreferrer">the path of purification</a>
maggāmaggañāṇadassanavisuddhiniddesa udayabbayañāṇakathā, <strong>Master
Sāriputta and Master Buddhaghosa</strong> describe udayabbaya as
paṭiccasamuppāda as well.</li>
</ol>

<p>So, yathābhūta-ñāṇa is understanding of arising of 5 aggregates in paṭiccasamuppāda-cycle. </p>

<p>Another, I also describe yathābhūta in this answer: <a href="https://buddhism.stackexchange.com/a/26702/10100">https://buddhism.stackexchange.com/a/26702/10100</a></p>

<p>Buddha have to cut the big sutta in DN/MN for the students who not smart enough to enlighten/understand/memorize at once. So, you can notice my reference are from DN&amp;MN&amp;SN&amp;KN, and actually AN as well.</p>

<p><strong>Pāli has a very strong structure. This is the reason why we can understand tipitaka's content by just fluent reciting&amp;memorizing.</strong> But because of the complicate detail of Dhamma, so when we translate tipitaka to the other languages, such as english or especilly thai, we will lose many important words' properties. Then we can not understand/analysis/find the fact from some translation.</p>

<p><em>"Svākkhāto bhagavatā dhammo-the best dhamma was taught by buddha." is not just the psalms, but it is the fact by the linguistics and the truth.</em></p>
