Grammar

Question 1

Periods & Semicolons

Answer 1

-Between two complete sentences
London is an old city; it has many new buildings.

• Before conjunctive adverbs such as however, therefore, or moreover at the beginning of a clause.
  London is an old city; however, it has many new buildings.

-Sentence Boundary
Incorrect: Barbara McClintock is a scientist whose discovery of “jumping” genes helped earn her the Nobel Prize in 1983, she won the award in Physiology or Medicine.

Question 2

COLONS AND DASHES

Answer 2

-Before a list
Visitors to London often spend their time in three main types of attractions: museums, castles, and shops.

-Before an explanation
When the Manchus took control of China, the Great Wall lost its protective purpose: the Chinese empire now extended well north of the wall, and its new enemies came from across the sea.

When a colon or dash separates two sentences, as is common in explanations, it is grammatically identical to a period or semicolon.

Question 3

COMMA + FANBOYS

Answer 3

-Comma + FANBOYS = Period = Semicolon
London is a very old city, and it is very appealing to tourists.

-Comma Splices (incorrect)
Tip-off: comma + pronoun (e.g., it, they, s/he, one, you, I)
(incorrect)
London is a very old city, it has some extremely modern parts.

-Comma + FANBOYS + Verb = WRONG