GRAMMAR: Adverbs of frecuency

Adverbs of indefinite frequency tell us how often something happens.

Common examples are:   always, ever, usually, normally, often, frequently, seldom, never

Position of AdverbsAdverbs of indefinite frequency go in mid position. They are normally placed after the auxiliary verbs and before other verbs. When there are two auxiliary verbs, the adverb goes after the first.

Examples:

a. I always get up early.    (adverb + main verb)

b. I am seldom late for work.    (is/am/are/was/were + adverb)

c. We frequently visit them.    (adverb + main verb)

d. I often read comics.    (adverb + main verb)

e. I have never seen a dolphin.    (auxiliary verb + adverb + main verb)

NOTES:1. Usually, normally, often, frequently, sometimes and occasionally can also go at the beginning or end of a clause.Examples:

a. We visit them occasionally.

b. Often we trust the wrong person.


2. Always, ever, rarely*, seldom* and never can go only in mid position. (exception* look #3)
Examples:

a. They never admitted their fault.

b. You can always trust him.


However, always and never can begin imperative clauses.
Examples:

a. Always look before you leap.

b. Never ask her about her age.


3. Rarely and seldom can also go at the end of a sentence (often with "very"):
Examples:

a. We see them rarely.

b. John eats meat very seldom.


Found via: Tx.english-ch