The period of time is in the singular form, for example: Day/Week/Month/Year/Night
The day of the week is in the plural form

Frequency adverbs

Adverb definition

gives more information about the verb

Example

without an adverb

Sara is walking

with an adverb

sara is walking quickly

types of adverbs

Adverbs of indefinite frequency

Always

100%

Frequently

90%

Ussually

80%

Often

70%

sometimes

50%

Occasionally

40%

Subtopic

Seldom

20%

Rarely/Hardly ever

10%

never

0%

Adverb of definite frequency

Describe the exact frequency of an action

Day

Week

Month

Year

Morning

Evening

Night

Week

Fortnight

Position of the adverbs in the sentence

Adverbs of indefinite frecuency

Position of the adverbs

all the adverbs of indefinite frecuency can go before the main verb

I always play football

Jane seldom drinks alcohol

I have never met the Queen

if the main verb is the verb "to be" the verb is after the verb "to be"

Mark is often late

Ocassionally/sometimes/Often/frequently/ssualy
Can also at the beginning or the end of sentence

Sometimes i play football

Mark watches television occasionally

Adverb of definite frequency

Number + "times" + "a" + period of time

Example

if the number is one, then say "once" (not "onetime")

I wash my car once a month

if the number ostime is two, the we say "twice" (not "two times")

I go to London twice a year

"every" + period of time

Example

Jane calls her mother every day

Marks goes to the beach every day

"on" + day of the week

example

Andrew watches football on saturdays

my parents go to the cinema on Wednesdays

Asking a question about frequency

"how often" + question form of verb

example

How often do you play football?

How often does MArk wash his car?

When you lived in London, how often did it rain?

How often wil you write to me