まずい<span class='chui'>んだ</span><strong>もん</strong>。

怒（おこ）らないでね。<span class='vocab-popout' data-vocab-id='502'>子供（こども）</span><span class='chui'>なんだ</span><strong>もん</strong>。

<span class='vocab-popout' data-vocab-id='349'>僕（ぼく）</span>は<span class='vocab-popout' data-vocab-id='141'>そう</span><span class='vocab-popout' data-vocab-id='591'>感（かん）じ</span>た<span class='chui'>んだ</span><strong>もん</strong>。仕方（しかた）ないじゃない？

<span class='gp-popout vocab-popout' data-gp-id='24' data-vocab-id='519'>寒（さむ）い</span><span class='chui'>んだ</span><strong>もん</strong>。<span class='vocab-popout' data-vocab-id='1072'>風邪（かぜ）</span>をひいてしまう<span class='gp-popout' data-gp-id='78'>よ</span>。

「食（た）べすぎ！」って言（い）われても…、<span class='gp-popout vocab-popout' data-gp-id='24' data-vocab-id='888'>美味（おい）しい</span><span class='chui'>んだ</span><strong>もん</strong>！

<span class='name-highlight'>A: </span>たまは<span class='vocab-popout' data-vocab-id='231'>もう一度（いちど）</span>カーペットにおしっこした！<br /><span class='name-highlight'>B: </span>だって子猫（こねこ）<span class='chui'>だ</span><strong>もの</strong>。

<span class='name-highlight'>A: </span><span class='vocab-popout' data-vocab-id='170'>どうして</span>そんなに<span class='vocab-popout' data-vocab-id='1004'>遅（おそ）く</span>なったの？ <br />B:渋滞（じゅうたい）が起（お）きた<strong>もの</strong>。

<span class='name-highlight'>A: </span><span class='vocab-popout' data-vocab-id='170'>どうして</span><span class='gp-popout vocab-popout' data-gp-id='47' data-vocab-id='9'>あの</span><span class='vocab-popout' data-vocab-id='654'>時計（とけい）</span>を買（か）わなかったの？ <br /><span class='name-highlight'>B: </span>高（たか）すぎた<strong>もん</strong>。

<span class='name-highlight'>A: </span><span class='vocab-popout' data-vocab-id='170'>どうして</span><span class='vocab-popout' data-vocab-id='564'>彼（かれ）</span>と別（わか）れたの？ <br /><span class='name-highlight'>B: </span>だって、ずっと嘘（うそ）をついていた<strong>もの</strong>。

<span class='name-highlight'>A: </span><span class='vocab-popout' data-vocab-id='170'>どうして</span>コールしなかったの？　<br /> <span class='name-highlight'>B: </span>忙（いそが）しかった<strong>もん</strong>。

<span class='name-highlight'>A: </span>なんで<span class='vocab-popout' data-vocab-id='336'>何（なに）も</span>食（た）べないの？ <br /><span class='name-highlight'>B: </span>食（た）べたくない<strong>もん</strong>。

<span class='vocab-popout' data-vocab-id='567'>彼女（かのじょ）</span>は嘘（うそ）をついている<strong>もの</strong>。

Using 「もの」 as a casual feminine way to emphasize

<div class='writeup-body'><span class='gp-popout' data-gp-id='213'>もの</span>, an extremely common noun in Japanese that means 'thing', can also be used as a <span class='info-highlight' data-term='終助詞・しゅうじょし'>sentence ending particle</span>. In these cases, it adds a small amount of emotion to a statement, and presents it as a reason. Due to this, <span class='gp-popout' data-gp-id='213'>もの</span> is usually translated as 'because', or 'cause'. Literally, it just means 'it's an (A) thing!'. <span class='gp-popout' data-gp-id='213'>もの</span> is quite casual, so should be avoided in formal situations.<br>To use <span class='gp-popout' data-gp-id='213'>もの</span> as 'because', attach it to the end of the <span class='info-highlight' data-term='終止形・しゅうしけい'>plain form</span> of any word.<ul class='writeup-examples--holder'><li class='writeup-example'><div class='writeup-example--japanese'>あなた<span class='gp-popout' data-gp-id='44'>が</span>言（い）う事（こと）は何（なに）も信（しん）じられ<span class='gp-popout' data-gp-id='51'>ない</span>わ。<span class='gp-popout' data-gp-id='452'>だって</span>、あなたはいつも嘘（うそ）<span class='gp-popout' data-gp-id='21'>を</span>つく<span class='gp-popout' data-gp-id='213'>もの</span>。</div><div class='writeup-example--english'>I can't believe anything you say. Cause you always lie.</div></li><li class='writeup-example'><div class='writeup-example--japanese'><span class='gp-popout' data-gp-id='452'>だって</span>、彼女（かのじょ）<span class='gp-popout' data-gp-id='10'>が</span>悪（わる）いんだ<span class='gp-popout' data-gp-id='213'>もの</span>。</div><div class='writeup-example--english'>Cause she is the one in the wrong.</div></li><li class='writeup-example'><div class='writeup-example--japanese'><span class='gp-popout' data-gp-id='5'>これ</span>はあなたにあげられ<span class='gp-popout' data-gp-id='51'>ない</span>。大切（たいせつ）だ<span class='gp-popout' data-gp-id='213'>もの</span>。</div><div class='writeup-example--english'>I can't give this to you, cause it is important.</div></li><li class='writeup-example'><div class='writeup-example--japanese'>すぐ泣（な）く<span class='gp-popout' data-gp-id='524'>に決（き）まってる</span>じゃん、<span class='gp-popout' data-gp-id='72'>まだ</span>こどもだ<span class='gp-popout' data-gp-id='213'>もの</span>。</div><div class='writeup-example--english'>Of course he will cry, cause he is still a child.</div></li></ul>To emphasize <span class='gp-popout' data-gp-id='213'>もの</span> even further, the explanatory んだ (after a verb or <span class='gp-popout' data-gp-id='24'>い-Adjective</span>), or なんだ (after a <span class='gp-popout' data-gp-id='28'>な-Adjective</span> or noun) will often be used.<ul class='writeup-examples--holder'><li class='writeup-example'><div class='writeup-example--japanese'>エアコン<span class='gp-popout' data-gp-id='21'>を</span>つけて寝（ね）<span class='gp-popout' data-gp-id='765'>ている</span>よ。<span class='gp-popout' data-gp-id='452'>だって</span>、暑（あつ）くて寝（ね）れ<span class='gp-popout' data-gp-id='51'>ない</span>んだ<span class='gp-popout' data-gp-id='213'>もの</span>。</div><div class='writeup-example--english'>I sleep with the A/C on. Cause it's so hot that I can't sleep, you see.</div></li><li class='writeup-example'><div class='writeup-example--japanese'><span class='gp-popout' data-gp-id='30'>この</span>子（こ）は失敗（しっぱい）する<span class='gp-popout' data-gp-id='524'>に決（きま）ってる</span><span class='gp-popout' data-gp-id='9'>でしょう</span>、<span class='gp-popout' data-gp-id='72'>まだ</span>新人（しんじん）なんだ<span class='gp-popout' data-gp-id='213'>もの</span>。</div><div class='writeup-example--english'>Of course this kid will make mistakes. Cause he's still new here.</div></li></ul><div class='writeup-caution'><div class='caution-header'>Caution</div><span class='gp-popout' data-gp-id='213'>もの</span> can be shortened to <span class='gp-popout' data-gp-id='213'>もん</span> in its use as a sentence ending particle. However, this makes the statement sound far more 'cute' or 'childish'. Due to this, it should be avoided in standard conversation.<ul class='writeup-examples--holder'><li class='writeup-example'><div class='writeup-example--japanese'><span class='gp-popout' data-gp-id='42'>もう</span>お腹（なか）いっぱいだ<span class='gp-popout' data-gp-id='213'>もん</span>。</div><div class='writeup-example--english'>Cause I'm already full.</div></li><li class='writeup-example'><div class='writeup-example--japanese'><span class='gp-popout' data-gp-id='7'>いい</span>よ、お前（まえ）<span class='gp-popout' data-gp-id='955'>と</span>は<span class='gp-popout' data-gp-id='42'>もう</span>遊（あそ）<span class='gp-popout' data-gp-id='888'>ばない</span><span class='gp-popout' data-gp-id='213'>もん</span>！</div><div class='writeup-example--english'>It's all good! I'm not going to play with you anymore! (Showing mild anger/jokingly)</div></li></ul></div><div class='writeup-funfact'><div class='funfact-header'>Fun Fact</div>Although it is not used regularly in standard Japanese, ん<span class='gp-popout' data-gp-id='2'>です</span>もの is a slightly more polite version of んだもの that appears frequently in anime, manga, and novels.<ul class='writeup-examples--holder'><li class='writeup-example'><div class='writeup-example--japanese'>こんなものすぐに壊（こわ）れるに決（き）まっているじゃない<span class='gp-popout' data-gp-id='2'>です</span>か、紙（かみ）<span class='gp-popout' data-gp-id='52'>から</span>出来（でき）てるん<span class='gp-popout' data-gp-id='2'>です</span><span class='gp-popout' data-gp-id='213'>もの</span>。</div><div class='writeup-example--english'>Of course something like this will break instantly. (Because) it is made of paper.</div></li><li class='writeup-example'><div class='writeup-example--japanese'>しょうがない<span class='gp-popout' data-gp-id='2'>です</span>よ、<span class='gp-popout' data-gp-id='47'>あの</span>人（ひと）は何（なに）も考（かんが）えてい<span class='gp-popout' data-gp-id='51'>ない</span>ん<span class='gp-popout' data-gp-id='2'>です</span><span class='gp-popout' data-gp-id='213'>もの</span>。</div><div class='writeup-example--english'>We can't help it. (Because) that person doesn't think about anything.</div></li></ul></div></div>

Grammar Info

もの・もん

because, cause