'БЛАГОДАРИТЬ' (Imperfective aspect) // 'ПОБЛАГОДАРИТЬ' (Perfective aspect) - to thank - благодарить (за что?), - to express gratitude for attention – благодарить за внимание.

Imperfective verbs - Present, Past and Future tenses. Perfective verbs - Past and Future tenses, no Present tense.

In the first comment you can find PDF-file with all the forms in the sentences. You can download this file for free)))