Present Perfect with already, still, yet, just, ever and never

Explanation about present perfect using already, still, yet, just, ever and never (uses and examples). 

Simple Past, Past Continuous and Used to

Explanation about the uses of simple past, past continuous and used to (while when and just when), grammar structures and examples. 

Modals and Semi Modals

Explain the use and differences between modal verbs and semi modals. 

Present Perfect Simple and Present Perfect Continuous

Explain about the use, differences and examples of present perfect simple and present perfect continuous.