Correct sentence: The tip of your tongue often tastes sweet at first.
Why this is better (easy explanation):
- "The tip of your tongue" is the part we are talking about.
- "tastes" is the action (what it does).
- "often" tells us this happens many times.
- Adding "at first" makes it clear it happens at the beginning, before other parts of the tongue taste things.
Another way to say it: "At first, the tip of your tongue often tastes sweet."
Both versions are correct. Use whichever sounds nicer to you!