〇〇 was very lucky to have you as his/her first teacher.
★情報処理プロセス："子供の初めての先生があなたで良かった"と言いたい→まずは【骨格抜きの術】で【だれがどうなの】という骨格を抜き出します。この場合、主語になるのはそのお子さんの名前か、親御さんも含めてWeでもよいですね。→【だれがどうなの】→【私たちがラッキーだったの】→必ず次は【接着剤】です。何がラッキーだったかというと、【持つことができて、あなたを、最初の先生として】なので、【動詞をくっつけるための接着剤】であるtoですね→ 〇〇 was very lucky to have you as his/her first teacher.
I'm so glad that my child could have you as a teacher!
"Glad" is another way to say "happy" and we often use it to talk about situations that make us happy. "Could have" is the best phrase to use because your child could have had a different teacher but they had this specific teacher. I hope that this helps. :)
"glad" は "happy"（うれしい）の別の言い方です。うれしく出来事について使われます。
ここでは、別の先生になっていた可能性もあるわけなので、"could have" を使うのがベストです。
Of all the good teachers my child could have had, I'm glad you were the first.
I'm so pleased my child was lucky enough to have you as his / her first teacher.
The first phrase is a polite, if slightly formal, way of saying this, as it does not make it seem that the other teachers she could have had where inferior. It still lets the teacher know that the parent preferred them, without being disrespectful to the others.
The second phrase is much more conversational in telling the teacher how you feel, and highlights "pleased" and "happy" as key words.
二つ目のフレーズはそれよりもはるかに口語的です。自分の気持ちを伝えて、キーワードとして "pleased" や "happy" を強調します。
It great that you were my child's first teacher!
I'm glad that you were my child's first teacher
My child couldn't have asked for a better teacher than you!
To your child's teacher at school, you want to say something like "I'm glad that you were my child's first teacher". try one of the above suggested statements,according to your context.
子どもの学校の先生に、"I'm glad that you were my child's first teacher"（子どもの初めての先生があなたで良かった）のようなことを言いたいということですね。
It's fortunate that you were my child's first teacher
I'm glad that my child's first teacher was you.
My child is lucky that you were her/his first teacher.
I'm glad that my child's first teacher was you. - the word "glad" means to be happy. You could also say "it's fortunate that..."to say that good things happened.
My child is lucky that you were her/his first teacher. - the word "lucky"means success or good fortune brought by chance, not on purpose. So your child had success getting a good teacher for their first teacher.
I'm glad that my child's first teacher was you.（うちの子の最初の先生があなたでよかったです）
→"glad" は「うれしい」という意味です。他に、"it's fortunate that..."（...というのは運が良い）でも「よかった」の気持ちを表せます。
My child is lucky that you were her/his first teacher.（あなたが最初の先生だったなんてうちの子は幸運です）
I'm glad you were my child's first teacher
I'm happy to have you as my child's first teacher
If you are pleased about something then you can say you are 'glad' or 'happy' about it
When starting school your child's first teacher would be the first person they met that teaches them so it's very important they are happy with them
「うれしい気持ち」は 'glad' または 'happy' で表せます。
I'm so glad that my child had you as their first teacher.
"I'm" is the shortened version for "I am" which is useful in this informal context. I would use the word 'so' to sound more enthusiastic about what you are saying. "glad" simply means 'happy'. You could also swap this word for happy, thankful, or lucky. 'had you as their first teacher' is the simplest way to state that the child has the teacher for their first year at school.
"I'm" は "I am" の短縮版です。このようなカジュアルな場面で有効です。
"glad" はシンプルに 'happy'（うれしい）の意味です。"glad" の代わりに "happy" "thankful"（感謝している）または "lucky"（幸運である）も使えます。
'had you as their first teacher' は「子どもの初めての先生があなただった」の最もシンプルな言い方です。