Pronouns in English

What was the mistake in the sentence "How did she learn it?" when referring to a Chinese friend whose gender is unknown?

• The use of "did"

• The use of "learn"

• The use of "she"

• The use of "it"

Which pronoun should be used instead of "his" in the sentence "Oh no, somebody has forgotten his umbrella!" if the owner's gender is unknown?

• her

• their

• its

• him

Are you enjoying the video lesson?

• Yes

• No

After which of the following words is singular 'they' commonly used?

• I

• You

• Everybody

• We

When was the first written example of singular 'they' found in English?

• 1944

• 1594

• 1813

• 1375