suspicious

Compared meaning: doubtful, not trustworthy (adjective).

比较义项：可疑的，不可信的（形容词）。

• suspect

  Suspect describes a statement, claim, or piece of reasoning that seems possibly untrue or unreliable; it is fairly formal and mostly used as a predicate (seem/sound/look suspect), less often to describe a person's manner.

  suspect 语气较为正式，多作表语，用来形容某种说法、理由等看起来不真实或不可靠，不像 suspicious 那样常用来形容人的举止。

  The reasoning behind his alibi sounded suspect once the detective checked the timeline.

  警探核实了时间线之后，他不在场证明背后的推理听起来很可疑。

• questionable

  Questionable expresses doubt about whether something is honest, correct, wise, or of good quality; it typically modifies decisions, methods, ethics, or motives rather than a person's look or behavior.

  questionable 侧重对某件事是否诚实、正确或恰当表示怀疑，常用来修饰决定、方法、道德等，而不是用来形容人的外表或举止。

  Cutting corners on safety checks was a highly questionable decision by the contractor.

  承包商在安全检查上偷工减料，这是一个非常可疑的决定。

• suspicious 本词

  Suspicious is the everyday, most common word; it describes behavior, appearance, or circumstances that make people suspect wrongdoing, or a person's own wary, distrustful feeling toward someone.

  suspicious 是这三个词中最常用、最口语化的一个，多用来形容人的外表、行为或处境让人觉得可疑，也可表示某人自己怀疑、提防某事或某人。

  The cashier gave the man a suspicious look when he paid entirely in small bills.

  那名男子全部用零钱付款时，收银员向他投去怀疑的眼神。

Suspect, questionable, and suspicious all mean 'doubtful'. Suspect is formal, describing a statement that seems untrue. Questionable doubts a decision or motive. Suspicious, the most common word, describes a person's look or behavior that seems wrong. Suspect can mean 'a person believed guilty'; not compared.

这三个词在“可疑的”这一义项上意思相近，但语气和用法不同：suspect 较为正式，多作表语，形容说法、理由等看起来不真实或不可靠；questionable 侧重对决定、方法、动机等是否正确、诚实或恰当表示怀疑；suspicious 是最常用、最口语化的词，多形容人的外表、举止或处境让人觉得有问题，也可表示某人自己心存疑虑。此外，suspect 还常作名词，表示“嫌疑人”，这里不作比较。