Usually I have no appetite in the morning, and so I just eat some fruit or a yogurt. Usually I have no appetite in the morning, and so I just eat some fruit or a yogurt.

If I need to do some physical work, I prefer to eat some bread with jam. (I like orange jam with orange peel ion it). If I need to do some physical work, I prefer to eat bread with jam. I like orange jam with orange peel on it.

If I need to do physical work, I prefer to eat some bread with jam (I like orange jam with orange peel in it). If I need to do physical work, I prefer to eat some bread with jam (I like orange jam with orange peel in it).

The language is correct here but we normally call "orange jam" marmalade. It's a special case in the names for jam. Another synonym for jam is "preserve" and you might see this word sometimes in a supermarket or something.

If I need to do physical work, I would prefer to eat some bread with jam (I like orange jam with orange peel in it). If I need to do physical work, I would prefer to eat some bread with jam (I like orange jam with orange peel in it).

The addition of "would" sounds more natural and grammatical to me. In my experience, hypothetical sentences such as this one tend to use such words.

When I was a kid, my grandpa would prepare hot milk and a kind ofwith special biscuits for my breakfast. When I was a kid, my grandpa would prepare hot milk with special biscuits for my breakfast.

When I was a kid, my grandpa would prepare hot milk and a kind of special biscuits for my breakfast. When I was a kid, my grandpa would prepare hot milk and a kind of special biscuit for my breakfast.

... a kind of THING. ... a type of THING. ... a sort of THING. All singular because they describe the kind rather than referring to the (multiple) biscuits themselves. It gets more complicated if you want there to be many kinds: ... many kinds of biscuit/s. <---- can be singular or plural ... all sorts of things. <---has to be plural ... multiple strains of bacteria. <--- singular Sorry I can't give a better explanation of how this works. Maybe you just need experience from context to know the right construcion.

When I was a kid, my grandpa would prepare hot milk and a kind of special biscuits for my breakfast. When I was a kid, my grandpa would prepare hot milk and a kind of special biscuit for my breakfast.

The biscuits are dry when eaten on their own, but they taste delicious when they're soaked in milk. The biscuits are dry when eaten on their own, but they taste delicious when they're soaked in milk.

I used to love it, but...after eating them for breakfast for three years, I got tired of them. I used to love it, but...after eating them for breakfast for three years, I got tired of them.

To be honest, now I miss them, because I can't buy them in the city I live. To be honest, now I miss them, because I can't buy them in the city.

To be honest, now I miss them, because I can't buy them in the city I live in. To be honest, now I miss them, because I can't buy them in the city I live in.

There's a missing preposition here. You don't "live" a place; you "live in" a place.