Always

 What is "always"? 

Always is an adverb of frequency and length of time. It's generally used in middle position in the clause.

1. Frequency

As an adverb of frequency always means "on all occasions", "at all times" with the present simple. Let's see examples below:
1. The train is always on time.
2. Sam and Susan always visit their grandparents on Sundays. (= "They visit them every Sunday")

With the present progressive form (or continuous) (be + always + Verb-ing) always means "continually". We often use it to describe a habit we don't like. Let's see examples below:
1. John's always smoking.
2. My father is always losing his smart key.

2. Length of time

In this case, always means "for all time". Let's see examples below:
1. Have you always lived in the country? (= "all your life")
2. The USA and EU will always be best friends.

I hope this article helps. If you have any question, please leave a comment below.