Undercut Vs. Undermine Vs. Underline:
Undercut, 是削弱或是賣價低於...。
Costco can undercut Carre-four and RT-Mart.
好市多能賣得比家樂福和大潤發便宜。

Undermine,是損害權威。
You shouldn't undermine your boss by publicly disagreeing with him.
你不應該公眾跟你老闆表示異議, 這樣有損他的權威。

Underline,是在...下面劃線、強調或是使...更明顯。
The recent mass shooting underlines the need for tighter gun control.
最進的大規模射殺案更明顯得表現出我們對更嚴緊的槍支管理上的需求。

Cross Vs. Across:

Cross主要當名詞或動詞而Across只能當副詞或介係詞, 令外呢, Cross動詞字意常用於交叉或是越過, 但Across就無交叉的意思,而當做穿過只能當副詞用,而介係詞用於在…四處、在…的另一邊、在…的對面或是從一邊到另一邊。
She thought you were impatient because you crossed your arms the whole time.
因為你從頭到尾都交叉著手臂, 她以為你不奈煩呢。
You need to cross this street to get there. = You need to walk across this street to get there.
你要到那裡需越過這條街。(Cross當動詞, Across當副詞)
The restaurant is across from the building.
餐廳就在建築物對面。
Gym Factory fitness centers are located across Taiwan.
健身工廠 健身中心台灣四處都有。

Prompt Vs. Impromptu:

Prompt, 提示、激起或是迅速的。
Please be prompt whenever we have an emergency.
每當我們有緊急狀況, 請動作敏捷。
A login prompt can be helpful when you forgot that you have already logged out.
當你忘了你已登出,登錄提示滿有幫助的。

Impromptu, 即席的, 臨時的。
We threw an impromptu party last night.
我們昨晚臨時辦了個派對。

Delusion Vs. Illusion:

Delusion是妄想而Illusion是錯覺或是幻覺。
Both a delusion and illusion are not real. When you have a delusion, you believe in what normal people don't; when you have an optical illusion, other people mostly likely perceive the same as you do.
妄想與錯覺都不是真的。當你有妄想時, 你的認知與一般人有出入;當你有光幻覺時, 其他人極可能看到的是跟你一樣的。

Tour de force Vs. De facto:

Tour de force, 傑作。
Ju Ming's sculptures are contemporary tours de force.
朱銘的雕刻是當代傑作。

De facto, 實際的。
Democracy means liberty is de facto.
民主意味著實際上的自由。

Beyond Vs. Behind:

Beyond, 在更遠處、超出。
Most people don't live beyond 100 years.
大多數人不活超過100年。

Behind, 在背後。
She is standing behind me.
她站在我後面。

Infrastructure VS. Structure:

Infrastructure, 是基礎建設。
Bicycle infrastructure could reduce traffic congestion.
自行車基礎建設也許能減少交通阻塞。

Structure, 是結構、建築物。
This building structure is very sturdy.
這棟建築物結構很堅固。

Implicate Vs. Complicate:

Implicate, 牽連、涉及。
If you are implicated in a crime that you didn't commit, the law works in a way that the prosecutor should not be able to prove you guilty beyond a reasonable doubt.
如果你涉及你沒犯過的罪, 起訴人在法律體係之下,應該沒辦法無可置疑得證明你有罪。

Complicate, 複雜化、使 …更嚴重。
To keep ourselves happy and healthy, we shouldn't complicate things in life.
為了要保持我們身心快樂又健康, 我們應避免把生活複雜化。

Suave Vs. Svelte:

Suave, 圓滑有禮。
A suave person is very likable.
一個圓滑有禮的人很討人喜愛。

Svelte, 是苗條。
He watches his diet in order to stay svelte.
為了要保持苗條, 他很注意飲食。

Compromise Vs. Promise:

Compromise,妥協、讓步。
Every good relationship needs compromise.
每個好的人際關係都需要有妥協。

Promise, 承諾。
You should keep your promises.
你應該守住你的承諾。

Wander Vs. Wonder:

Wander,漫步、迷路。
I spent the whole afternoon wandering around Taipei City.
我花了一整個下午閒逛台北市。
Kids can wander off on their own easily.
小孩很容易自己迷路。

Wonder,懷疑、想知道。
I wonder if the store is open on weekends.
我想知道店周末有沒有開。
I always wonder whether I made the right decision.
我總懷疑我做的這決定是對的。