WHO’S key is this? → ❌

WHOSE key 🔑 is this? → ✔

WHOSE crying right now? → ❌

WHO’S (who is) crying? 😭→ ✔

FACT: You can use “whose” with people AND objects:

I know a man *whose* dad is tall. → ✓.

I have a chair *whose* legs are broken. → ✓.

Fact:
In some expressions, English has no prepositions where one may be used in another language; in other expressions the opposite is true.

Friends, can you suggest me a way I can explain you that saying
"suggest me" or "explain you" is grammatically wrong ?

ALWAYS REMEMBER -
some verbs like "suggest" and "explain" can only have a second object if this is a prepositional object with "to". Observe these examples -
— He suggested me a plan (incorrect)
— He suggested a plan to me (correct)
— He suggested a plan (correct)
— Can you explain me the situation? (incorrect)
— Can you explain the situation to me (correct)
— Can you explain the situation (correct)
Other such verbs are - admit, announce, demonstrate, describe, introduce, mention, point out, prove, report, say, suggest.
if you consider the meaning of all these verbs, they will appear to be the members of a same family and this fact may help you to remember these words.