Read each pattern and its example, then write your own sentence on the line.
〜ことだから N（人）の + ことだから
Predicts what someone will do based on their known character: knowing him, he'll surely… Almost always used with a person the speaker and listener both know. Conversational.
彼のことだから、また遅れて来るだろう。 Knowing him, he'll probably turn up late again.
〜わけがない V / i-adj plain + わけがない；na-adj な + わけがない；N の + わけがない
States a confident denial based on reasoning: there's no way that could be true. Stronger than はずがない. Used freely in speech; わけない is the casual short form.
あんなに練習したのだから、負けるわけがない。 We practiced that hard, so there's no way we'll lose.
〜かねない V-masu stem + かねない（悪い結果のみ）
Warns that a bad outcome is quite possible: it could well end up that way. Only for undesirable results. Common in news, warnings and formal speech.
寝不足は大きな事故につながりかねない。 Lack of sleep could well lead to a serious accident.
〜かねる V-masu stem + かねる（丁寧形：〜かねます）
A polite way to say you cannot do something, because it is difficult or against the rules. Very common in business Japanese as 〜かねます, softer than できません.
申し訳ありませんが、その件はお答えしかねます。 I'm very sorry, but I am not able to answer that.
〜がたい V-masu stem + がたい（信じ／忘れ／理解し など）
Says something is hard to do because it goes against feeling or judgment, not physical difficulty. Written and formal; limited to verbs like 信じる, 忘れる, 想像する.
彼の話は信じがたいものだった。 His story was hard to believe.
〜得る / 〜得ない V-masu stem + 得る（うる／える）／得ない（えない）
States that something is theoretically possible or impossible. The dictionary form reads うる or える, but the negative is always えない. Formal and written.
誰にでも起こり得る問題だ。 It's a problem that could happen to anyone.