"Thinking" is the present participle of "think". Present participles always end in -ing.
The present participle of "think" is "thinking" and the past participle is "thought."
The present participle of think is thinking. Present participles always end in -ing.
I/you/we/they think. He/she/it thinks. The present participle is thinking.
Being is the present participle. The past participle is been.
Getting is the present participle of get.
The present participle is doing.
I think it is a present participle
Presenting is the present participle of present.
Presenting is the present participle of present.
The present participle is choosing.
The present participle is walking.
The present participle is cleaning.