Identify the word which is always singular.

Corrected answer: None of the given words is always singular.

Explanation:

• Innings — In cricket usage the form innings is used for both singular and plural. Examples: "He played a fine innings." (singular) and "They had two innings." (plural).

• Pants — A plural-only noun in normal usage (pluralia tantum). Example: "These pants are new."

• Trousers — Also plural-only in normal usage. Example: "Those trousers are comfortable."

• Goggles — Normally plural-only. Example: "My goggles keep fogging up."

Conclusion: Since the three items pants, trousers and goggles are plural-only and innings can be used both as singular and plural, none of the listed words is always singular. The original solution that selected innings as "always singular" is therefore incorrect; innings can function as singular but is not exclusively singular.