Present perfect progressive shows actions that started in past and continue into future. Shorter time frames use present perfect progressive, longer time frames use both tenses. Non-action verbs cannot take progressive form (-ing)
Indicates duration of ongoing actions from past to present. Shows recent actions with visible results
For indicates a period of time, which can be seconds to years. For can be used in past, present, and future tenses. For is used with vague periods like "for the weekend". For is used with periods of time in songs like "Frozen"
Present perfect connects past actions with present influence. Formed using 'have' present tense and main verb's past participle. Many languages have similar tenses but different usage
User questions why "at New Year" is used instead of "on New Year's Eve". "On New Year's Eve" is commonly accepted as a correct usage. "At New Year" is rarely heard in English
Both when and while can be used interchangeably in some sentences. Use while with progressive tenses for actions with duration. Use when with simple tenses for short, non-in-progress actions