Modal Verb Introduction

What are Modal Verbs ?
Modal Verbs are special verbs which behave very differently from normal verbs. Here are some important differences:
1. Modal Verbs do not take "-s" in the third person.
EXAMPLES:
He can speak Chinese.
She should be here by 9:00.
2. You use "not" to make Modal Verbs negative, even in Simple Present and Simple Past.
EXAMPLES:
He should not be late.
They might not come to the party.
3. Many Modal Verbs cannot be used in the past tenses or the future tenses.
EXAMPLES:
He will can go with us. NOT CORRECT
She musted study very hard. NOT CORRECT

Common Modal Verbs
Can; Could; May; Might; Must; Ought to; Shall; Should; Will; Would.