Online Exercise of Modal Verbs
https://www.english-grammar.at/online_exercises/modal-verbs/m015.htm
Online Exercise of Perfect Modals
https://www.perfect-english-grammar.com/could-have-should-have-would-have-exercise-1.html
Individual Online Exercise about the Adverbs of Degree
https://www.ecenglish.com/learnenglish/lessons/adverbs-degree
Online Exercise about Phrasal Verbs with the Preposition 'On.'
https://eflnet.com/pverbs/phrasalverbsOn
Collaborative Exercise about Classifying the Verbs followed by to-infinitive or -ing
https://wordwall.net/es/resource/62736657
Collaborative Online Exercise about Verbs followed by to- infinitive or -ing
https://www.englisch-hilfen.de/en/exercises/structures/gerund_infinitive2.htm
Individual Online Exercise about the use of 'too' vs 'enough'
https://test-english.com/grammar-points/a2/too-too-much-too-many-enough/2/
