Forming questions

This is a very good link, both for explanations of how to form questions and many exercises for practice.

1. Forming questions

https://www.english-4u.de/en/grammar/forming-questions.htm

https://www.englisch-hilfen.de/en/grammar_list/fragen.htm

https://www.englisch-hilfen.de/en/exercises/questions/form.htm

https://www.englisch-hilfen.de/en/exercises_list/fragen.htm

2. Tenses

present simple and present continuous

https://www.ego4u.com/en/cram-up/grammar/simpre-prepro

present perfect and present perfect continuous

https://www.ego4u.com/en/cram-up/grammar/prepersim-preperpro

https://www.perfect-english-grammar.com/present-perfect-present-perfect-continuous-1.html

You'll be able to ask questions in many situations.

Enjoy!