*SINCE = Often used with the perfect tenses-to indicate a particular time.
*FOR = Often used with the perfect tenses or the simple tenses to indicate a duration of time.
*YET = Often used with the perfect tenses -in negative meanings and in questions.
*ALREADY = Often used with the perfect tenses- In affirmative meanings.
*YESTERDAY = Often used with the past tenses.
*TODAY = Often used with the present tenses.
*TOMORROW = Often used with the future tenses or with the present continuous tense when it refers to the future.
*DURING = Often used with the simple and the continuous tenses to show a duration of time. Not usually used with the perfect tenses.
*OVER THE PAST FEW = Often used with the present perfect tense to indicate time starting in the past and continuing to the present.
*USUALLY = Often used with the present tense to indicate habitual actions.
*NOW = Used often with the present continuous tense.