Punctuation marks are symbols used to add pauses, stops & emphasise parts of sentences.
The comma - The University of Bristol
The comma splice - University of Bristol
The aprostrophe - The punctuation guide
Apostrophes (elementary to intermediate) - Factsheet UNE
The aprostrophe - University of Bristol
Quotation marks - The punctuation guide
Exercise on quotation marks - OWL, Purdue
Semi-colon (elementary to intermediate) - Factsheet UNE
Semi-colons - The punctuation guide
The semi-colon - University of Bristol
The colon - The punctuation guide
The colon - University of Bristol
The difference between brackets & parentheses - Lexico, Oxford
Brackets - The punctuation guide
Parentheses - The punctuation guide
Test your punctuation skills (intermediate, advanced) - Grammar monster
Exercises on punctuation (intermediate, advanced) - Learn English