In "Limbo" and "Two Lorries," Seamus Heaney shows how women are often dehumanized by the culture in which they live, utilizing literary techniques such as metaphor, imagery, enjambment, and diction. Let's look at this in more detail.
In "Limbo," some fisherman find a dead baby. The speaker says that the child was illegitimate, and he thinks about how the baby may have ended up there. His mother threw this "small one" into the waters. Yet this doesn't seem to be an act of maliciousness, but rather of despair. The mother stands in the shallows "Ducking him tenderly." She apparently does care for the child, but she has no hope left.
The baby is a "minnow with hooks," tearing open his mother from the inside out—perhaps physically, perhaps emotionally, perhaps both. She wades into the water, suggesting that she probably committed suicide along with the murder of her child. This is an example of metaphor, but it is also arguably also an example of imagery, as the image of the "minnow with hooks" is quite vivid.
This woman seems to be less than a human being to the society in which she lives. She has an illegitimate child, and she appears to have run out of options. Heaney speaks of the child using the metaphor of a fish, for it seems like society cares more about fish than about this baby and his mother.
In "Two Lorries," the speaker begins with a flashback. He recalls a day when it is raining and the coalman Agnew is flirting with his mother. Perhaps she will go to a movie with him in Magherafelt, but she will have to decide quickly, because, in an example of enjambment, "it's raining and he still has half the load // To deliver farther on."
The speaker's mother is impressed by this offer. Apparently she doesn't get to go to the movies much, and she is moved by the "tasty ways of a leather-aproned coalman." This is an example of diction, with the descriptive word of tasty, and of imagery, as readers can vividly picture the "leather-aproned coalman."
This interest is understandable, perhaps, for this woman likely lives a pretty dull life and is longing for a bit of excitement, yet it does make her appear to be less than a person, at least in the coalman's eyes. He can hardly even wait for her answer, and he seems confident that his city ways will charm her.