I am learning English preposition "to" that is used before the noun that describes a reaction or answer.

I have a few sentences with this construction. I would like you, English native speakers, to check this sentences and answer such questions as:
Are these sentences grammatically correct and can be used on exams ?
Can these sentences be used in everyday English speech ?

So there are the sentences:

I don’t have a reply to that. — У меня нет ответа на этот вопрос.
We expect that the current session will find a proper solution to this problem. — Мы ожидаем, что текущая сессия сможет найти правильное решение этой проблемы.
It could be an allergic reaction to something. — Это могло быть аллергической реакцией на что-то.
It is the key to so many medical solutions. — Это ключ к решению многих медицинских задач.

Question

I am learning English preposition "to" that is used before the noun that describes a reaction or answer.

I have a few sentences with this construction. I would like you, English native speakers, to check this sentences and answer such questions as:
Are these sentences grammatically correct and can be used on exams ?
Can these sentences be used in everyday English speech ?

So there are the sentences:

I don’t have a reply to that. — У меня нет ответа на этот вопрос.
We expect that the current session will find a proper solution to this problem. — Мы ожидаем, что текущая сессия сможет найти правильное решение этой проблемы.
It could be an allergic reaction to something. — Это могло быть аллергической реакцией на что-то.
It is the key to so many medical solutions. — Это ключ к решению многих медицинских задач.

Mercz · Answer

To: is used for a reason something was done for.

I stopped at the bakery to buy some bread.

To : just phrase.

The key to the door.  The key to success.

To : when you give something to somebody. It is the same in both ways.

Give the book to her.
Give her the book.

To : with compound verb or phrasal verb:

I looked to my parents for support.

To: to go to/towards a person or place you wish.

They went to the stadium yesterday.

To: when we want to talk or speak to somebody.

I was talking/speaking to your dad about starting up in business.

To / towards: be kind or nice to somebody.

He was very nice to her.

Any doubts. Let me know. Friend.

Ask native speakers questions for free