Questions about example sentences with, and the definition and usage of "Lack"

A: ”It didn’t fail because I didn’t try. Believe me, I tried!”

Lack means missing/short
If there was a lack of trying, it means someone didn’t try hard enough.

A: Like you don’t have enough of something or Deficiency

A: to not have or not have enough of something that is needed or wanted:
He just lacks a little confidence.
What we lack in this house is space to store things.
We are lacking three members of staff due to illness.

A: lack = to be short of, to be in need of, without, absence of
(por ejemplo: ausencia o carencia)

Example:
She is lacking good manners.
A lack of nutritious food in your diet can make you sick.

A: It means that you did your best even if you fail.

A: Notice how "common sense" and "sympathy" are nouns? That's when you wouldn't use "in," but when you are using an adverb (can be signified with the ending "~ly") you would use "in". You could say "She lacks creativity," or "She lacks in creativity." Either one could work, but you can't use "in" for things like "common" sense.
correct: "They lack common sense."
incorrect: "They lack in common sense."

A: Lacking a spine is being cowardly and maybe behaving in a way that makes them seem weak
Being “spineless” or “lacking a spine” is an insult and it means that you aren’t strong enough to handle something
Person 1: “I’m too scared, I can’t watch that scary movie”
Person 2: “you’re spineless”

A: You can say "I'm suffering from lack of sleep".

I'm suffering from lack of interest.

There was a distinct lack of supporters at baseball today.

A:
1. You lack common sense.
2. I lack vitamin D.
3. There is something lacking in that painting.
4. There is a lack of wind in that area.
5. What are you lacking?

A: "Lack" used as a verb
For example: This university lacks famous professors.
Another example: Our love lacks passion.

"Lack" used as a noun
For example, The lack of water is going to be a problem in our daily life.
Another example: The lack of money is going to be a problem for buying a new computer.

A: I’m doesn’t make sense grammatically. You are technically saying “I am lack of responsibility.” You cannot be a lack of responsibility, but you can have a lack of responsibility. So, the best way to phrase that sentence would be “I lack responsibility.”

A: lack is a verb, insufficient is an adjective.

A: No you can't, because "I am" means that you're talking about what you are, not what you have. If you want to use "am", you can say "I am not experienced enough for this kind of job." a lack cannot be something you are, it can only be something you have.

A: For the pronunciation, lack sounds like 'whack' or 'back' It has a hard 'ack' sound.

Luck on the other hand has a 'uh' sound. So Luh-uck.

A: Lack is an absence, something is missing.
A drawback is a negative feature. A thing that is there but you wish wasn't.

A: Well...now that you say it...we do not have a word for that.
I say “strategiless” sounds good though. 👍
We make new words all the time anyway.

A: No courage / coward
(용기가 없다 / 겁쟁이)

A: No courage / coward
(용기가 없다 / 겁쟁이)

A: Having too little or too much money negatively influences people’s views.

A: It’s not redundant and you can’t leave it out.

(If you say “causes problems” then you have to leave “is” out, but this also slightly changes the meaning.)

A: Ok. 미국에서 The statement in your initial question would be unnatural. Lack=a deficiency or an unmet need. I’m sorry that the other user failed to address that. You could say, “He will never lack the resources that are required to support such a lavish lifestyle.” But honestly, we would say something like, “He’ll always have enough to live the good life” in everyday conversation.👍

A: “or maybe a lack in inspiration to run, maybe it’s just cold out, or hotter”

A: Essentially, yes 😅

Obviously in sentences where it expresses direction or the recipient of an action it's always going to be a preposition, but in cases like this you just have to know. If it helps though I really struggled to think of examples so it won't come up often

A: × I'm lack of energy.
✓ I'm lacking [the] energy.

or... "I lack [the] energy."

either one is correct with or without the article "the". Add it depending on the context of the rest of the expression.

But, probably the following would be a bit more natural in conversation:

"I don't have [the] energy..."

Again, it depends on the way you'll be using it.

I hope that helps!

A: × I didn't exercise, and a lack of protein today.
✓ I didn't exercise today, and I didn't get enough protein.

"I'm reflecting about that" sounds perfectly natural by itself. But, I'm not sure it quite captures the feeling of what you put in Japanese. Honestly, in this situation, I would probably just say, "Oops" or maybe, "I'll do better tomorrow."