Valmiki Ramayana Aranya Kanda Sarga 72 Shloka 18
Original Shlokaस च ते नावमन्तव्यस्सुग्रीवो वानराधिपः।।3.72.18।। कृतज्ञः कामरूपी च सहायार्थी च वीर्यवान्।
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वानराधिपः (अपि सन्) king of the monkeys, सः सुग्रीवः that Sugriva, ते by you, नावमन्तव्यः not to be insulted, कृतज्ञः a grateful one, कामरूपी च he can take any form at will, सहायार्थी च he seeks your help, वीर्यवान् strong.
Thinking that Sugriva is only a vanara king, he should not be disrespected. He has a sense of gratitude. He can take any form at will. He is in need of your help although he is very strong.