يا ترى الخطا فين:When the plane took off, she held my hand strongly.

held my hand tightly

اليك منى كل احترام وتقدير
When the plane took off, she held my hand tightly.
Strongly is used with verbs such as suggest, advise, recommend,
agree i disagree, believe, feel etc (NOT with verbs that refer to actions):
'I would strongly advise you to think again.'