We use Present Simple to refer to an action or event that takes place regularly or habitually in the present. However, we have different frequencies, including marginal frequencies like never and always. As a result, actions or events take place at different frequencies. That is why, we can use Present Simple with signal words describing different frequencies of actions or events:
always, constantly, frequently, usually, often, sometimes, rarely, never
We normally place this word before the verb:
I usually come home exactly at 5.
However, if it is the link verb “to be” in its Present Simple form am / is / are, we usually place it after the link verb.
I am always tired.
To work on Frequency words: Present Simple:
Emphatic sentences: He comes home late. Always. He never comes late, ever.
Sometimes position: Sometimes, he is late.
More on Present Simple: